In your case, there is no need to deduct TDS, as the single bill amount does not exceed Rs. 30000/-. But during the year if the aggregate AMC bill goes above Rs. 75000/-, then you shall have to deduct TDS u/s 194C. TDS @ 1% if deductee is an Individual or HUF and TDS @ 2% if the deductee is a Pvt. Ltd. or a registered P'ship Firm.
In this case, there is need to deduct TDS, as the single bill amount exceed Rs. 30000/-. But during the year if the aggregate AMC bill goes above Rs. 75000/-, then you shall have to deduct TDS u/s 194C. TDS @ 1% if deductee is an Individual or HUF and TDS @ 2% if the deductee other then, like company,firm.