According to the Contract Labour (Regulation and Abolition) Act, 1970, the contractor is primarily responsible for providing leave to the contractual staff. As per the Act, every worker who has worked for a period of 240 days or more in a year shall be allowed leave with wages for a number of days calculated at the rate of one day for every twenty days of work performed by him during the previous year.
However, as a principal employer, you have an indirect responsibility. If the contractor fails to provide the benefits, then it becomes the responsibility of the principal employer to provide the same.
The Delhi Shops and Establishments Act, 1954, also provides for leave entitlement for workers. According to this Act, an employee is entitled to one day of leave for every 20 days of work subject to a maximum of 15 days in a year.
Please refer to the following circulars for more information:
1. Contract Labour (Regulation and Abolition) Act, 1970 -
http://clc.gov.in/clc/acts-rules/con...ition-act-1970
2. Delhi Shops and Establishments Act, 1954 -
http://www.delhi.gov.in/wps/wcm/conn...ments+Act+1954
Please note that these laws are subject to change and it is always advisable to consult with a legal expert or labor law consultant for the most accurate information.