Indian boy and foreign girl - needed documents

Dear Sir or Ma'am, my respectful Namaskars!

I want to marry an Indian boy so wanted to know which documents i should submit for legal marriage.

I stay in India for almost 4 years, i am a student.

In between 4-5 times i visited my country. But last one and half year staying in India.

So do i need to go back to my country for getting some documents?

Something like document which proves that i am not married?

Thank You!

Sincerely,