In lateral entry... I can try 

Dear Raja, there are about 700 colleges that offer Bachelor's in Automobile Engineering in India. Here is their list: https://engineering.careers360.com/colleges/list-of-automobile-engineering-colleges-in-india

While few colleges take admissions based on State Level Entrance examinations, few conduct admissions based on National Examinations like JEE Mains & Advanced. Then few Institutions also take admissions based on your GATE scores. Different states have different State Level Entrance Examinations like MHT CET, NATA, WBJEE, etc. Manipal University has MUOET and Tamilnadu has TNEA. So most of the Entrance Examinations allow Diploma students to take up their Entrance Examinations. And few don't have any upper age limit. So please go through this list and do let us know if you have any college that you have in mind so that we can help you further. 

Hii raj
Its great you have done DIPLOMA in mechanical , yeah
After diploma, you can go with degree level courses or PG diploma programs. B.Tech degree can be obtained with specialization in Automobile Engineering or Automobile design Engineering. Admission to the course can be done through lateral entry and thereby you can save one year. Post Graduate Diploma in Automobile Engineering is also suitable for you. Or else you can try for a job with railways, defense, government departments etc.



Regards