The Commissioner of GST & Central Excise challenged a CESTAT order that allowed Ascendas IT Park (Chennai) Ltd to avail full CENVAT credit on input services under Rule 6(5) of the CENVAT Credit Rules, 2004, for the periods 16.06.2005 to 01.06.2007 and April 2009 to March 2010. The Department argued that credit was wrongly availed in respect of Renting of Immovable Property (RIP) services, which were exempt during the relevant period. The Madras High Court upheld the CESTAT's reasoning, holding that Rule 6(5) permits full credit unless the services are used 'exclusively' in relation to exempted services, and since the assessee also rendered taxable services, the exclusivity condition was not met. The Court also agreed with the Tribunal's rejection of Board Circular No. 98/1/2008-ST as erroneous and irrelevant for the post-01.06.2007 period. Substantial questions 1 and 2 were answered in favour of the assessee; question 3 was returned unanswered due to absence of submissions, and question 4 regarding service tax on fit-out charges was not fully resolved in the extracted text.