Percentile is 70 and rank is around 302000

The percentile / rank which one can expect depend on many factor like category, number of student applied, difficulty level of exam etc. So it varies from year to year with respect to marks obtained.

Though it is difficult to tell rank but with previous years rank analysis we can give you an idea about the rank which youn can expect.

As you have not mentioned your category considering you a general category candidate you can expect an Overall Percentile in between 91.8 - 92.0 for 75 marks out of 300 in paper 1.

With this percentile your rank can be in between 73527 - 85677

To know the chances of admission in different colleges with the expected rank you can use college predictor tool -

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

hope it helps.