Urgent help: service tax on commercial and training coaching classes

I AM RUNNING A COACHING INSTITUTE OF 2 FLOORS.GROUND FLOOR AND 1ST FLOOR IS USED FOR CLASSES AND THE 2ND FLOOR IS USED FOR HOSTEL PURPOSE. THERE IS NO COMPULSION FOR EVERY STUDENT TO BE IN HOSTEL. THOUGH THE FIRM IS SAME BUT STILL TWO DIFFERENT RECEIPTS ARE BEEN GIVEN ONE AS A TUTION FEES AND OTHER AS A HOSTEL FEES RECEIPTS. THE HOSTEL RECEIPTS IS ONLY APPLICABLE FOR THE STUDENTS WHO ARE IN HOSTEL. NOW MY QUESTION IS THIS WHETHER SERVICE WOULD BE APPLICABLE ON HOSTEL FEES ALSO AS HOSTEL IS A NON TAXABLE SERVICE . WHETHER CLUBBING PROVISION WOULD BE APPLICABLE AND WHOLE FEES WOULD BE CONSIDERED WHILE CHARGING SERVICE TAX. PLZ HELP WITH RELATED CASE STUDY. AND TELL HOW TO SAVE SERVICE TAX ON HOSTEL THEN