tds on building rent

Hello. .I am working with a public sector bank at present.
Our branch is located in a college campus hence we pay the rent of rs.18000 to the college in their account.
no tds has been deducted ever on their rent till date and when I joined this branch I asked why the tds is not deducted on the building rent college provided me with a certificate from the local authorities that they are exempted from any kind of tds being a state owned educational instituition .
In the certificate it is mentioned that tds on interest on Fds is exempted but there is no mention of exemption of tds on building rent.
I want to clarify if there is any section available stating that building rent of an educational instituition is exempted from tds?
kindly reply.i am really in the middle of an official mess.