According to your class 12 marks and jee marks you do not fall in the eligibility criteria of the college. As the minimum marks for the admission in class 12 are 75% required and jee rank around 10000 will do for the course in engineering field. Though you go for the counselling where after the making of the merit list, you will be able to know the confirmation about your admission. Go through the link for the further details for VNIT and admission in there.

https://www.shiksha.com/b-tech/course/b-tech-in-mechanical-engineering-vnit-nagpur-visvesvaraya-national-institute-of-technology-61687          

Hey Sahil,

Congratulations On qualifying JEE-MAINS-2019.

As you have scored 51% in 12th So please check if the college accept It as most time College has Criteria of 60% with some relaxation to SC/ST. If it is satisfied then it's fine. As mechanical seats are nowadays in lesser demand as CS/IT are most Crowded.

Here is a link to predict your College

https://engineering.careers360.com/jee-main-college-predictor?ici=search_trending

Best of luck