I was debating on what university should I apply to since both has very good reputations in Thailand. But I would like to ask some of your opinions on what school is better to study in based on honors, facilities, students, teachers, education and more. 

KMUTT is better

Mahidol has a decidedly better reputation in general. The kids from the best secondaries shun Mongkut, but it's one of the few universities in Thailand that is moving up in it's ranking yoy.

 

I'm unaware Mongkut has anything bio?? Labs?

 

Check QS for subject, take it with a grain of salt.

 

Consider Hong Kong. Some excellent value but far more competitive, far better education.