Income tax on csr expenses

Dear Expert,

My client is taking Unipol from one of the NGO having registration under section 80 G of IT Act  on hiring basis and given the same to his client by adding some margin. The above said transaction is duly supported by valid agreement between parties. This Unipol is being used for print advertising in the form of hording. The NGO is not raising any invoice and whenever payment is being made by my client, NGO has issued Donation receipts. Presently my client is deducting TDS @ 2%. Now NGO has approached to my client for not deduction of TDS on this type of transaction and request to show it as CSR expenses. My client is not covered under CSR obligatory list. My querry in this regard is that:-

1. NGO is giving donation receipts are sufficed for claiming expenses?
2. Is it allowable expenditure under Income Tax Act?
3. Whether TDS is applicable on payment made to NGO?

Thanks in Advance

CA Manoj Kr Karna