Tata Mahindra has a dedicarted career portal for the same. You can register there and complete all the requirements. Link - https://careers.techmahindra.com/Forms/Registration.aspx

For TATA Motors - 

A person can get a job in tata motors either through campus placements or through lateral entries. Tata Motors visits top engineering and management schools for recruiting young minds. If you have some experience please apply directly through tata motors website or get referred through a tata motors employee. The other way is post your resume on websites like naukri and monster from where it is get picked up by head hunting companies who provide these resumes to tata motors for further processing.

If you are a student and tata motors doesn’t visit your college I will suggest you to participate in ‘mindrover’ competition organised by TML and you can win a chance for pre-placement interview and who knows maybe you can convert it into a job opportunity.

These types of companies hires either via campus placements or through recruitment agencies.

• If you get hired through campus placement in such Oem's then it is the best you can get without much struggle.
• For the other way, you must find yourself a suitable GET job in a Tier-1 or Tier-2 company. Have some relevant experience of atleast 2 years in any specific domain and then try applying in these OEMs through recruitment firms.

While you peruse a decent job in a Tier-1 supplier with good skill set in your resume, you may find yourself contacted by OEM HR representatives themselves. Crack down their interview and get through .

Also a good GATE score in India, plays a very vital role to get in core companies.

hii,

You Can search in tata mahindra vacancy details in that particular website