Can an NRI start a farm or agribusiness in India even without owning the land?

Yes. The restriction is on owning agricultural land, not on doing agriculture. An NRI who wants to farm in India can take land on lease and cultivate it, since leasing does not transfer ownership. Many NRIs also enter agribusiness in ways that do not require holding farm land directly, such as setting up a food processing unit, a cold storage, a nursery on non agricultural land, an agri input business, or investing in a company or FPO that does the farming. Some allied activities also have their own treatment. The cleanest path is usually: lease the cultivable land with a proper written agreement, run the operations through a manager or POA holder, and keep the money flowing through an NRO account. If you want to invest at a bigger scale, look at structuring through a company, where the foreign investment rules for that sector apply rather than the agricultural land bar. Plan the structure with a CA and a lawyer so it fits both FEMA and the sector's investment rules. General guidance only.