Dear Chitra,
Firstly, CTC is just an accounting concept to assess the over all annual cost of employment per employee and as such it has no legal force.
Secondly, as far as I know, provision for HRA is not mandatory anywhere in India other than the State of Maharashtra where a special State Legislation on HRA styled as the Maharashtra Workmen's Minimum House-Rent Allowance Act,1983 is in force applicable to establishments under the Maharashtra Shops and Establishments Act and factories under the Factories Act,1948 in the State of Maharashtra only.
Thirdly, section 5 of the above Act clearly specifies that where a workman is provided with residential accommodation by the employer and no deduction is therefore made from his wages, the employer shall not be required to pay HRA to such workman.