We recently bought a piece of land in Trivandrum, registering it in my husband’s and his father’s name. Is it possible to transfer ownership to his younger brother as well?

Yes, you can add your husband’s younger brother as a co-owner to the land. This can be done through a registered deed of transfer, where the current owners (your husband and his father) transfer a portion of their ownership to his brother. A registered lawyer can assist with the process and ensure compliance with relevant property laws.