You can give student notice regarding pending fee and levying penalty on same in case they fail to pay fees you can give legal notice and without no des deny giving them degree and certificate.

You can also file suit to recover the amount.

You have final option of.filing suit if they fail to pay the amount.

You can send legal notice to each student on their home address along with fees due and interest. Mention otherwise legal action will be take by institute or college.

Meanwhile try inform all this matter to educational department of your state. And central home minister UGC department.

1) issue legal notice to students to pay the outstanding fees and collect their certificates 

2) if they fail to pay you can file suit to recover the fees but legal expenses would be more than fees sought to be recovered 

3) in future don’t permit students to appear for exams unless fees are paid 

Issue legal notice to students to pay the fees and collect their certificates 

Send a demand letter to all these students, who have not paid the fee till date.

If they still do not pay, send a legal notice to each of them. 

Student below 18 years can not enter into any valid contract. So no dues can be lawfully claimed from them by you.  As to students aged 18 or above you can lawfully claim provided the claims have not been time barred .

Dear Sir,

Get issue legal notice to the students and their parents and thereafter file civil suit for recovery of fees which is dues.

Fees are taken in advance, why u you permitted late fees. 

Well, without certificate their years spend on course is waste. Either issue them all a common letter to collect certificates by paying remaining fees or you shall be constrain to I initiate legal action for recovery of dues fees.

You address letters to the defaulters parents asking them to clear the  dues and  collect the certificates.

In case  if  they fail to do so, you make a requisition to the Board of Secondary to permit you to withhold their  certificates  viz., TC, Mark Sheet and other relevant certificates till they clear the dues.

Once this  is done  you will have at lease some people reacting  and it  keeps moving.

You may take legal recourse to recover the money for which firstly legal notice would be issued by your advocate and thereafter, a civil suit for recovery of due amount with interest would be filed on your behalf. 

issue a notice on institution letter head  to the pay fee immediately and collect certificates. if there is no reply then issue a legal notice through an advocate. 

The remedy in your hands is to file a suit for recovery of money in the competent civil court to seek the fee along with interest and cost of litigation.

You can send them notice and claim the money through recover suit

You should serve students legal notice to clear the outstanding fees and collect certificate.

If they fail to clear outstanding amount you can file recovery suit against them. 

Dear Sir,

It is purely a contractual claim as such you can file a common suit for recovery of dues of fees and it will be decreed . Then you can execute the same by attaching properties of parents of such students .

You first issue a legal demand notice to the students.

After that you may file a money recovery suit.

Yes, college fees only, if you have documentary evidences about the defaulting students, you may proceed legally as suggested.

There are plenty of answers to your question.