is there any chance to get a good college in 60 percentile in jee mains 2021 (obc)

With 60 percentile, your estimated CRL rank will be in the range 4,30,000-4,50,000 and category rank will be around 1,50,000. Sorry to say but you have negligible chances of getting into any NIT or IIIT. But you can try for private engineering colleges accepting jee mains score or attempt the paper again next year. Note that various private engineering colleges conduct their separate entrance exams like LPU, SRM, VIT, etc. Check out the link below to explore college options.

https://engineering.careers360.com/colleges/list-of-private-engineering-colleges-in-india-accepting-jee-main

Good Luck !