Hi Ashish,
I gave GMAT twice. In my first attempt I scored a 660. I was very depressed. But instead of withdrawing from the battle, I prefer to stay on and face the GMAT boldly. I belong to a place which does not have the luxury of good GMAT prep Course so I decided to build up my own strategy and follow the strategy strictly.
In my first attempt I could easily identify my problems.
1. Time management : I was not able to finish my test on time and I had to rush through the end questions.
2. RC's and CR''s : For a complete Strategy for RC's and CR's, please check the link below.
https://www.beatthegmat.com/710-rc-cr-tips-t43916.html
So, you see I neglected SC part and still managed to score 710 (even I made some big mistakes in Quant section) and I still continue to aspire for 780+.
Number of attempts are immaterial if you are able to perform consistently well. As for chances of admission is concerned, Although I am not an expert in the admission field but I would say if I were you I would definitely retake because you belong to IIT(Indian IT male- the most over-represented group!)
You need to first identify your weak areas where you need to work and how things got wrong. I would be able to offer you a customise solution once you let me know which areas you need to work.
Hope this Helps.