what %ile i accept if i get 50 marks in 27 1st shift August attempt ?
Considering the difficulty level of your shift, your predicted CRL is around 2,50,000 or near 75 percentile. With this percentile, you have very low chances of getting any NIT or IIIT ( assuming you belong to the general category ). You can try other colleges accepting jee mains score or attempt again next year.
Check out the link below to explore college options.
https://engineering.careers360.com/colleges/list-of-engineering-colleges-in-india-accepting-jee-main
Good Luck !