Hello aspirant!
Answering your question-

You are comparing two very different fields, there is no best, but one is best for you. To answer your question, take a look inward at yourself, and think about what you would find more fun and interesting. Do you have a natural skill or ability that would apply to one of then better?

There are two critically important factors for success in a career:

an intense interest or passion for it

a natural ability or aptitude for it

The main thing is that you know yourself, and visualize going to work every day to do the same thing and never getting bored. Once you learn about what you really want, youll be much more motivated and focused on doing it.
Hope this helps you.

Hey !
Automobile engineering will suit students who are interested in design, working and manufacturing of vehicles and their parts. Having skills such as sketching, imagination, creativity. After completing your Graduation...diploma and certification courses in Computer design will also help graduates.Salary packages are generally between 3-5 lakhs per annum.
Bio technology will suit students who are interested in engineering, technology and biology. Average  Salary package Can range from 2.5- 5 lakh per annum.
Both of the above fileds are quite different, so choose the one which seems interesting  for you and in which you feel that you can have a bright future.
Hope this helps
All the best !