In most of the engineering entrances, there are no age limit or attempt limit. So yeah! If you wish you can obviously take admission to the course of BTech and if you complete the course of Mechanical Engineering then getting a job will not be much of a problem. You must focus more on skills. Getting a marks in BTech is required but having a good skill set will be a more valuable point for securing a job. You should also focus on the Programming languages as well because the jobs opening in the core sector of ME is lesser compared to the IT sector. So if you have good coding skills, then you can easily land a job in IT sector.

For more information regarding a career in Mechanical Engineering consider the link provided below:

https://www.careers360.com/courses/mechanical-engineering-course

I hope this helps. Wish you a great eve!