Question

why does sun rise 2 hours earlier in arunachal pradesh compared to gujarat

Answer 1

 The local times of places which lie on different meridians are bound to differ. The sun rises two hours earlier in Arunachal Pradesh as compared to Gujarat in the west. This causes a time lag of two hours from Gujarat to Arunachal Pradesh. To avoid confusion due to time differences and to have a standard time for reference, the time along the meridian (82° 30' E) passing through Mirzapur (Uttar Pradesh) has been taken as the standard time for the entire country. This is why the watches show the same time.

Answer 2

It happens for the sole reason that the time for India land is measured with the standard meridian of 82.5 degree which passes through Allahabad. This was done to avoid any confusion in timing.