THE RAILWAYS ACT, 1989 – Chapter V – Section 27

27. Use of Rolling Stock

A Railway administration may use such rolling stock as it may consider necessary for the construction, operation and working of a Railway;
Provided that before using any rolling stock of a design or type different from that already running on any section of the Railway, the previous sanction of the Central Government shall be obtained for such use;
Provided further that before giving any such sanction, the Central Government shall obtain a report from the Commissioner that he has made a careful inspection of the rolling stock and, in his opinion, such rolling stock can be used.

Forward reference⇒Section 28