Whether CSR expenditure of a company can be claimed as a business expenditure?

No, the amount spent by a company towards CSR cannot be claimed as business expenditure. Explanation 2 to section 37(1) of the Income Tax Act, 1961 which was inserted through the Finance Act, 2014 provides that any expenditure incurred by an assessee on the activities relating to CSR referred to in section 135 of the Companies Act, 2013 shall not be deemed to be an expenditure incurred by the assessee for the purposes of the business or profession.