80DDB. Where an assessee who is resident in India has, during the previous year, actually paid any amount for the medical treatment of such disease or ailment as may be specified in the rules made in this behalf by the Board—
(a) for himself or a dependant, in case the assessee is an individual; or
(b) for any member of a Hindu undivided family, in case the assessee is a Hindu undivided family,
the assessee shall be allowed a deduction of the amount actually paid
or a sum of forty thousand rupees, [60,000 for senior citizen]
whichever is less, in respect of that previous year in which such amount was actually paid :
Deduction can be claimed upto the limit specified not for full 15 Lacs
Provided that no such deduction shall be allowed unless the assessee furnishes with the return of income, a certificate in such form, as may be prescribed, from a neurologist, an oncologist, a urologist, a haematologist, an immunologist or such other specialist, as may be prescribed, working in a Government hospital
"“Government hospital” includes a departmental dispensary whether full-time or part-time established and run by a Department of the Government for the medical attendance and treatment of a class or classes of Government servants and members of their families, a hospital maintained by a local authority and any other hospital with which arrangements have been made by the Government for the treatment of Government servants;"
Usually those people who got their treatment from govt. hospital dont have trouble in this and many few people opt for this because if any portion of the cost is paid by insurance then deduction is reduced (max to the extent of insuarance amount)
Format
https://www.incometaxindia.gov.in/forms/income-tax%20rules/103120000000007200.pdf