#1. I scored 330/504 marks in JEE Advanced 2015(~65%). Could anyone please estimate my rank?

#2, My interest lies in Elec. Engg. But almost everyone is warning/urging me not to go for it saying it’s tough and it would take away my social life. Is it COMPLETELY true?

Considering the difficulty level of the paper compared to last few years, your rank would surely be below 500.
There is no such thing as elect. would  take you away from your social life, pursue any stream in which your interest lies.

Just listen to your inner voice, make up your mind to pursue the study program that you are interested in and do the right....mind you whatever you may choose, one thing is for sure that you will have to work hard, thus, it hardly makes difference whether you choose electrical/comp. sci/ mechanical or civil. i may suggest you some of the elite class colleges/universities  – 

Cambridge Inst of tech, Ranchi

Lovely Professional University, Phagwara

JJTU, Rajasthan

BITS, Pilani

your rank would be around 200.

BEST of luck