Yes,police checking is done for visa confirmation,as it is 
mandatory,its to see if you have any criminal records.
checkin is generaly done by police data base,and they do 
check personally,but no personal interview is done.its not 
a hassel,if u dont have any records with the law.they give 
you a letter stating that there is no criminal records 
against you.that letter has to be submitted to the embassy 
of the country you are applying the visa for....

cheers

A simple format is available with the passport office for 
police verification. This is available in passport web 
site. Apply in that proforma and you will normally get 
within 3 days, if your passport is older. If your passport 
is new and is one or two months old, you will get this 
clearance certificate within a day. This applies to Indian 
context