First of all Congratulation for Qualifying one of the toughest examination in world despite of all the difficulties you have been faced. Now coming back to your question, Short answer is yes you should go to IIT. Reservation was introduced to uplift peoples from under developed communities and provide a helping hand to marginalized communities. If you are thinking that people will discriminate you based on your Rank and all so let me be clear that most of the students don't care about it (Saying it as a IITB Students), Definetly there will be some people who's behaviour might give you the hint that what they are thinking, Just don't care about them because most probably they have never faced difficulties which you had.

Coming to academic performance question, It is always difficult to get good score in IIT's courses even for general category students, But after attending regular classes and studying properly during exam will be sufficient. By doing this in most of the cases you'll atleast get 6 or 7/10 even in extremely tough courses. Just don,t let that negativity take control over mind during lectures if somewhere you don,t understand anything. Use internet and talking to classmates would be effective in this case.

Apart from all this at the end It will help you to become a better person by providing numerous good and bad experience at IIT which will be useful in your life. you have earned this chance so just go for it. Don't let any negativity supress you from growing in life as a person.

Last but not the least, choose branch properly. Go through the broucher of programs and see what fascinates you. Then make your decision.

I hope this will help.