SPJIMR PGPFMB (Post Graduate Programme in Family Managed Business) is a better and clear choice between the two.
This program was launched by SPJIMR in the year 1997, so it is quite a renowned program. This program has a network of 4000+ alumni to take guidance from. This program offers a classroom learning experience, and it last for 18 months.
The fee for the program is 16 lac for 18 months. While the GFMB program was launched recently by SP Jain Global, so if you have a choice, then I would recommend you to go for PGPFMB.