what is the difference between autonamus and affiliated collage wich is better
Autonomous colleges have an opportunity to design their own courses and syllabus. While an affiliated Institute has to run the course and syllabus prescribed by the University.
It totally depends on college to college that which is best. You can't compare colleges like this.
Do you want to compare any college?
According, to Careers 360 it has AAAA ratings which means very good.
To know more about the college you can refer below link
https://engineering.careers360.com/colleges/rmk-engineering-college-thiruvallur
Good Luck!!