Hi Kumar,

Yes, after scoring 50.17 percentile in JEE Main Exam you are eligible for JEE Advanced Exam if you are from SC category. Please make sure that your percentile is above 50.1760245, otherwise you won't be eligible.

The minimum percentile for admission into NITs in CSE or ECE branch in 98 percentile.

Refer here for more info - https://engineering.careers360.com/articles/jee-main-cutoff

To know your other best admission possibilities of Institutes & branches in JOSSA & State counseling as per your percentile, You can use JEE Main College Predictor tool given below

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!