Akshay, you have not mentioned which examination board you belong to. So I will be answering for CBSE board. In case the question was intended for some other board, please mention it in the comments.

For 12th board examination, you can get the sample question papers of Maths from the official website of CBSE. You can get the model papers of 2019 on the given link: http://cbse.nic.in/curric~1/qpms2019/qp12-2019.html You can click on the subject name to download the set of model papers.

For more previous year question papers and model papers from 2013 to 2018, you can go to the below link and download your preferred set: http://cbse.nic.in/newsite/examination.html