Get excise exemption

Hi Every one,

I am working AIIMS, jodhpur this is a Central autonomoncy body. we are a non profit org. we purchase lot of medical equipment and or other item inwhich excise are included.

My query is that can we take any certificate from Excise department that no budy charge Excise on purchase of our item in other words can we purchase excise free goods.

please help us and reply me.