if your playing full ring then limp anything upto 99
in lp with few limpers raising 77,88,99 is an option, but be sure to know when to put down post flop.
TT/jj are many peoples nightmare hands. For me id play and raise in all positions hoping for a favourable flop and a pot you have built up.
if you play six max then id suggest making a raise with any pocket pair due to the limited amount of hands available
really IT DEPENDS on position with 77-99 if you can limp or are in ep/mp then limp and see a reasonable raise. but if you think you can steal the pot preflop then try by raising
hope i helped