Section 6(3)(a) in Delhi and Ajmer Rent Control Act, 1952
(a)the landlord may lawfully increase the rent payable by the tenant-(i)in the case of any premises let for residential purposes, by an amount not exceeding twelve and one-half per cent. of the standard rent of the part sub-let;(ii)in the case of any premises let for other purposes, by an amount not exceeding twenty- five per cent. of the standard rent of the part sub-let;