which college of mechatronics charges low fees ?

In my opinion I would say NIT Trichy would be the best option you've got. It is one of the few colleges that offers this course in the country. This degree will have a better value when done from an NIT. Plus the placement packages are good here too. You may expect the semester fee to be around 60000. But again you dont have to pay the fee if you fall under the income below 5 lakh category.