If the rent payment is being made to two separate owners of the property, and each of them have a definite and ascertainable ownership to the property, the payment being made to each of the co-owner should exceed Rs. 1,80,000 to attract the provisions of Section 194-I
This has been specifically published in Circular No. 75 / 08.08.1995. This has also been highlighted in Senior Manager, SBI (2012) 206 Taxman 607 (All.)
Therefore, in your case above, if it can be proved that the two owners, do in fact, have separable identity and individual and segregated ownership in the collective property, no TDS needs to be deducted.
In the second case, any property owner receiving rent exceeding Rs. 1,80,000 per annum is liable to have TDS deducted under section 194-I. Section 194-I works assessee-wise and not asset-wise. Therefore, in the second case, the deductee-assessee is receiving a rent exceeding 1,80,000 Rs/-, and therefore is liable for tax deduction at source. If the tenants are covered u/s 44AB, they would be required to deduct TDS under section 194-I. In any other case, no TDS is liable to be deducted.