Chaitu,
Why you want to start a dairy farm without any land?
Since you don't know about its viability of dairy in coastal area and wanted to do it on leased land.
My advise for you is to forget about dairy and know you first that what is your expertise and do something with your expertise. Please do not see success of some others and blindly follow it. I need to see your expertise here, but not seeking expertises from some other. Pls get back with your expertise for your feature.
All the best.
Regards.
SWAMY