Even with ST category, there's a remote chance you get into any NIT at 80 percentile. You may get NITs,IIITs through Home state Quota but it also varies depending upon the state in which you live.
You are qualified for JEE Advanced and hence you should try to score atleast 25% of the maximum marks to get a seat in IIT. (Qualifying cutoff is 17.5% and 5% subjectwise) That's all what I can say.
All the best!!!!
good to see you here,
With a percentile of 80 your rank in the common rank list would be more than 2 lakh and if you might have belonged to general category you wouldn't have even be qualified for the JEE Advance.But as you belong to ST category you have a chance to get into an NIT but not in a good NIT with a good branch.For more information about the closing ranks of the NIT,you can visit the careers360 website.
But you have a chance to get a seat in NIT , but not you required branch.
For more information visit the college predictor.