my son got 76.4 percentile in 7 th datefirst Shep . what is his rank and marks in jee mains.

It is difficult to predict the actual rank as it depends on various factors. But you can calculate your expected rank by this formula. Total 869010 students have appeared for the January Session Exam.

(100 - your total score) * (869010 /100). As your son have got 76.4 percentile. So the expected rank will be-
(100-76.4) * (869010/100).
Which is almost equals to 2.05 lakhs.
Also you can use our Jee Main rank predictor-
http://engineering.careers360.com/articles/jee-main-rank-predictor

Hii

NTA again as last year, it won't release the marks scored. It will only publish the rank of candidates.  So, for knowing the rank accurately,  wait till the last week of april for NTA to publish it. You can also get an idea of rank using this rank predictor https://engineering.careers360.com/articles/jee-main-rank-predictor

Hope it helps