You need not to pay any money to the college.  Issue legl notice to college instructing them to send the certificates within 7 days from the date of receipt of the notice, otherwise you would claim the damages.

Question is getting certificate

Apply to them

If they dont give

File an FIR stating the facts , get a copy , go to Police station alongwith some expereinced and aged person who will simply tell Police that you file an FIR with criminal content

get a copy and wait

SIR,

I HAD TAKEN ADMISSION IN ENG. COLLEGE IN BANGLORE,BUT AFTER FEW MONTHS I FELT SICK DUE TO JAUNDICE AND SINUS. I WAS UNABLE TO STAY ALONE IN BANGLORE,SO I LEFT THE COLLEGE. I HAVE PAID ALL THE FEES FOR THE FIRST YEAR AND SUBMITTED THE DOCUMENTS. AFTER LEAVING COLLEGE NOW WHEN I AM ASKING THEM FOR MY DOCUMENT THEY R NOT GIVING IT BACK. THEY R TELLING I HAVE TO PAY FEES FOR ALL 4 YRS. THEN ONLY I WILL GET IT BACK. AS MY DOC. ARE NOT WITH ME  I CANT DO ANY THING. WHAT STEPS SHOULD I TAKE IN THIS CASE, PLEASE SUGGEST

Surprisingly, many colleges, especially Btech colleges, are adopting this policy for extorting more money from the students. I would file an FIR in police station and it would be better that several students jointly file an FIR against the institute. 

Apply to them throgh Registered AD , thro POST OFFICE , NOT Courrier  

Give them 15 days

Tell them blankly if they dont , An FIR will be filed against the Adsmn naming the Principal , Secy and the Admin Officer

Wait and Watch

If they dont , Go to the nearby Police Stn

They may not entertain

Get the name of the Police Ofiicial and the Station Sup

Post a FIR thro Registered AD thro POST OFFICE and wt for ack

if no ack comes write to Police Commr with all the copies , cc to Home Mister and CM of the State and wat and eatch

Make it a point to intimate every move to College Authorities with all copies

I feel you can get results quickly

With regards ,

Apply to them throgh Registered AD , thro POST OFFICE , NOT Courrier  

Give them 15 days

Tell them blankly if they dont , An FIR will be filed against the Adsmn naming the Principal , Secy and the Admin Officer

Wait and Watch

If they dont , Go to the nearby Police Stn

They may not entertain

Get the name of the Police Ofiicial and the Station Sup

Post a FIR thro Registered AD thro POST OFFICE and wt for ack

if no ack comes write to Police Commr with all the copies , cc to Home Mister and CM of the State and wat and eatch

Make it a point to intimate every move to College Authorities with all copies

I feel you can get results quickly

With regards ,

To get back your certificates from the college click https://userfriendlymails.blogspot.in/

Better you send a legal notice through a lawyer giving 10 days time and then if they not respond then approach court for claiming damages and to get order against their harasement.