Question

which longitude is considered as the Standard Meridian of India name the place from where it is passes

Answer 1

Indian Standard Time is calculated on the basis of 82.30' E longitude, in Shankargarh Fort, Mirzapur (25.15°N 82.58°E) (in Mirzapur district in the state of Uttar Pradesh) which is nearly on the corresponding longitude reference line.[2]

In the tz database, it is represented by Asia/Kolkata.