Hi Srinivas
As per serial no 74A of notification 12/2017-CTR which is the service exemption notification it seems to be exempt from GST too:
Services provided by rehabilitation professionals recognised under the Rehabilitation Council of India Act, 1992 (34 of 1992) by way of rehabilitation, therapy or counselling and such other activity as covered by the said Act at medical establishments, educational institutions, rehabilitation centers established by Central Government, State Government or Union territory or an entity registered under section 12AA of the Income-tax Act, 1961 (43 of 1961).
If not, even the person supplying the rehab services can be said to be a authorised medical practitioner exemption under serial no. 74 may be available. If values are significant and notice is issued, suggest to obtain written opinion and litigate the matter. Exemptions will be available for such activities.