Which article provides special provisions with respect to Delhi?

Article 239 AA of the Indian Constitution provides special provisions with respect to Delhi.

Some important provisions of Article 239 AA are:

• As from the date of commencement of the Constitution (Sixty-ninth Amendment) Act, 1991, the Union Territory of Delhi shall be called the National Capital Territory of Delhi (hereafter in this Part referred to as the National Capital Territory) and the administrator thereof appointed under article 239 shall be designated as the Lieutenant Governor.
• There shall be a Legislative Assembly for the National Capital Territory, and the seats in such Assembly shall be filled by members chosen by direct election from territorial constituencies in the National Capital Territory.
• The total number of seats in the Legislative Assembly, the number of seats reserved for Scheduled Castes, the division of the National Capital Territory into territorial constituencies (including the basis for such division) and all other matters relating to the functioning of the Legislative Assembly shall be regulated by law made by Parliament.
• There shall be a Council of Ministers consisting of not more than ten per cent of the total number of members in the Legislative Assembly, with the Chief Minister at the head to aid and advise the Lieutenant Governor. 

Further Reading:

• Union Territories
• List of Important Acts that Transformed India