Yes, you can file RTI to Tata Institute of Social Sciences. The Tata Institute of Social Sciences (TISS) is a multi-campus public funded research university in Mumbai, India. In 1944, the institute was officially renamed as the Tata Institute of Social Sciences and in 1964, the Government of India declared TISS as Deemed university under Section 3 of the University Grants Commission Act (UGC), 1956. Hence TISS is a "Public Authority" as per Section 2 (h) of the RTI Act 2005 and comes under its ambit.
The application can be filed to the designated Public Information Officer under section 2 (f) and 6(1) of the RTI Act 2005 with requisite fees.
To know more about the procedure o file RTI Applications in the State of Maharashtra, please refer https://onlinerti.com/how-to-file-rti-online-for-maharashtra