I think it's 1964. Ford Frick's last year of Commissioner is 1965. Inducted in 1964 were Heinie Manush, Burleigh Grimes, Red Faber, and Luke Appling.
Looks like all four are sitting on the right side of the table as you look at the photo. And where (sayhey24) says Heinie Manush is, it look like the same suit he has on in the photo below.
1964 Baseball Hall of Fame inductees