my son got a percentile of 99.23 OBC. what are the colleges where he can get thro.

Hello, he got decent percentile. Based on the category, he can get into top colleges. He has chances to get in top NITs, IITs & IIITs.
Expected cut-off for this year is given below.

- Common Rank List (CRL) - 90- 95 Percentile
- GEN-EWS - 70- 75 Percentile
- Other Backward Classes (OBC-NCL) - 70- 75 Percentile
- Scheduled Caste (SC) - 50- 55 Percentile
- Scheduled Tribe (ST) - 40- 45 Percentile
- PwD - 1-2 Percentile

https://engineering.careers360.com/articles/jee-main-cutoff

https://josaa.nic.in/Result/Result/currentorcr.aspx

To predict which college your son has changes of getting, by using below given college predictor link.

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