Prapatti/Sharanagati/Surrender

"Upaayeshu Prapattishyaat" is one of the six phrases given by Kanchi Devaperumal to Thirukkachi Nambi, in response to Swami Ramanuja's questions to Him.  Yalgnavakya smriti that lists 12 upayas for moksha, mentions "nyasa" as the 12th.  Nyasa is the same as Prapatti.

Having recognized that He is the only Swatantran, and that all Jeevatmas are paratantrans, we surrender that little-bit swatantryam that we thought was ours at the feet of the Lord.  This is Sharanagati/Surrender.  However, this is an institutionalized process in Swami Ramanuja's Srivaishnava Sampradayam which is mostly followed in the South of India.  What we are indirectly saying to the Lord is - "I have understood Moksham is the final destination of the Jeevatma,  but based on the criteria you have established for the Jeevatma to reach that destination by its effort, it is near to impossible (viz. exhausting all karma - positive and negative), therefore Lord, please accept my inability to go any further down the paths of Karma, Jnana, and Bhakthi - you are what I want, and you are the means for achieving it - please grant me Moksha".

Deciding to perform this Sharanagati/Surrender is only the first step.  Having decided, we need to identify a suitable Guru/Master that can take us to the Lord, introduce us to Him, and be the mediator in the process.  Swami Ramanuja appointed 74 Simhasanadipati's that were empowered to perform this mediation on behalf of a jeevatmas that drop by their Ashrams/Mutts. They go by the name of "Jeeyar" in tamil.

The ceremony for sharanagati is called "pancha samskaram".  During the ceremony, the Jeeyar does everything needed on our behalf.  We only need to follow his instructions.  Once the samskar is done, it establishes the first relationship the Jeevatma acquires in its millions of years of existence - that with the Acharyan.  The relationship with the Acharyan does not end even after attaining Moksha.

In Swami Ramanuja's tradition, the Moksha is a result of the relationship we establish through the Acharyan with Swami Ramanuja's holy feet.

The worlds/Universes

Let us understand "Universe" for a moment here. The vedas say that each universe is egg-shaped and that there are many such universes. Each universe is situated above one of Seshnag's head. Seshnag has countless heads, and therefore there are countless universes. On a jovial side, one may wonder what would happen if Seshnag were to catch a cold and sneeze - will be universes tremble and shake? Well, the Lord has thought a way for that also - because he realized the such a huge snake when he even breathes the worlds will go up and down. so, just like we have shock absorbers in our cars, He placed the seven avarna waters as the padding on Seshnag's head, and then placed the universes on them. All these universes together are called the "changing worlds". It implies that the only thing constant and ever assured in these worlds is change.

The Lord, on the other extreme has also created a "permanent world" in which "changes" do not happen. The Lord himself is referred to as "Avikara" - one without change. This permanent world is called Sri Vaikuntha (the land of no diminishment).

Returning to the discussion on the tri-gunas, the changing worlds (all thousands of them) and everything in them are composed of the three gunas - sattva, rajas, and tamas. The permanent world and whatever it contains (all matter, all people, all everything) are composed of "shudda-sattva". The reason for calling it "shudda-sattva" is to distinguish it from the "mishra-sattva" (mixed sattva) that is present in the changing worlds.

Bhagvaan is everywhere and in everything

In English, people call it "God"...that word does not have any etymolology.  I prefer to use the sanskrit term "Bhagvaan" - it means that He has six main gunas -
Bha stands for two gunas - Gnana (Knoweldge) and Bala (Strength),
Ga stands for Aishwarya (Ability to command over everything) and Veerya (Ability to remain without change),
Va stands for Shakti (Being the material cause of everything) and Tejas (Ability to remain independent not needing anybody or anything's help to achieve its goals).

The "an" in the end denotes, one who is combined with these 6 gunas.  Advaiti says Brahmam is devoid of Gunas.  Bhagvaan has numerous, countless groups of Guans says swami Ramanuja.In any case it is easier to be devoted to someone who has excellent qualities like Grace, Kripa, Daya etc. than to be devoted to something or someone that does not have any gunas.

Every name in the world denotes the Bhagvaan.  Everything and Everyone that is called by a name - has an Atma in it.  That Atma is in turn owned by the Bhagvaan. Therefore every name on earth - whether you call the spade a spade or stone a stone, or a person by his/her name, all names (proper and common) denote the Bahgvaan.  Bhagvaan, as "antaryaami" resides within each Atma, commanding it, and owning it. No wonder, when you call me by my name or I call you by your name, the reference to you, takes me all way from the body which is known by that name, to the Atma that owns the body, to the Antaryami that owns the Atma.  Even if a person considers himself/herself as an atheist and denies the existence of Bhagvaan, even their names  denote the Bhagvaan - even within them, the Bhagvaan stays in their Atma as an Antaryami.  That is the reason we refrain from hurting other's feelings even if they have inadvertently hurt ours.