Dear Sri Sundeep,
Up to my knowledge, through gathered information, No hybrid variety of kala jamun (Indian blue berry) is released by any Indian university and /or became popular.
Only selections are brought to the Indian farmers, in which ’ Bahudoli ’ is one of the best variety and origin is learnt as university of Horticulture, Konkan area, Maharashtra. Giving very good results and appears to be the leading/popular in Maharashtra, AP, Telangana, Karnataka, Tamilnadu etc. Considerable good yield, taste and mainly fetching highest price in the markets. Well accepted by consumers.
Nurseries may say any thing but you can purchase bahudoli jamun plants from Horticulture university of Maharashtra, and/or from any reliable/authorised nursery.
I suggest you to plant one year plants, if you are planting in low density and plant 2 years or more plants, if you are making high density plantations.
Up to my knowledge, there is no comparison of jamun available in India, better than Bahudoli variety jamun. Only care you/every farmer has to take is reliable source of the plants. In fruit plants, more than cost, reliable plant is considerable, as the plants life will be decades together.
With best wishes, g.p.rao, farmer