Hello dear

After doing btech in mechanical engineering you can go for further studies in MBA, msc ,mtech,or you can do some other external courses or programme which will build your resume. Depending upon your interest you can opt any of the option .

Courses of coding like java , ML , AI , solid works etc may help you to get a good job or you may take experience in some technical companies and further you can switch in a good company.

Good luck