Please refer to Section 66F of the Finance Act, 1994 which reads as follows:
"66F (2) Where a service is capable of differential treatment for any purpose based on its description, the most specific description shall be preferred over a more general description.
(3) Subject to the provisions of sub-section (2), the taxability of a bundled service shall be determined in the following manner, namely:--
(a) if various elements of such service are naturally bundled in the ordinary course of business, it shall be treated as provision of the single service which gives such bundle its essential character;"
In your case, you are providing the Hostel accommodation along with mess facility and furniture facility. It's a case of naturally bundled services. The service which gives it the essential character is the hostel accommodation service, other services being incidental in nature (mess and furniture facility could be optional too). You may classify your service accordingly.