Question

does India need to have more than one standard Time

Answer 1

India is the second* largest country in the world that runs on a single time zone. Of the top 7 big nations, other than India and China, nations run on 3 or more timezones. India has considered multiple time zones a few times and figured it was not worth it.

Majority of India's major cities (Delhi, Bangalore, Hyderabad, Mumbai, Chennai) are relatively close to the central longitude. This is the same case for China, where most of its economy is centered around the Beijing longitude.
Proximity to equator (most big nations are in the temperate zone) meaning there is less of a seasonal variation in day length.
There is big problem of economic integration when there are multiple time zones. Communication companies, broadcasting companies, stock exchanges and travelers have to adjust to multiple zones.