Sir I got 66704 rank in JEEE mains my cast is OC. I need mechanical is it possible to get any NIT ?

Hello,
According to your rank and assuming that your are a open category aspirant , then you can get mechanical engineering in the north eastern nits like nit manipur, sikkim etc and other lower ranked nits too in the spot rounds done by csab round.
But you can't be sure of spot rounds seat because it highly depends on how many students are taking part in it and are there any seats remaining that college.
You can have a look on jee main college predictor.
https://engineering.careers360.com/jee-main-college-predictor
All the best!!!