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As per your query for ST category you percentile should be 34.6728999-87.8474721 to qualify JEE Main, to get CSE in Top NITs like in Trichy , Wrangal , Surathkal , Allahabad , Rourkela. you have to 95+ percentile for government colleges try to score 90+ percentile.

There is huge competition for Computer Science Engineering branch so try to give your best, to maximise your score in session 2 JEE Main try JEE Min Rank booster course checkout given link below:
https://learn.careers360.com/jee-main-rank-booster/

Hope you found it helpful
All the best!!