it is 6ft 6in, Medium power, Mod Fast

I am thinking to buy one for shallow to mid depth crank like rapala DT, bomber sth like that , even jerk  biat.

is it good for those kind of cranks?

thanks

I don't see any reason that the rod would not work for those applications.

For the cranks it would be Ok . For jerks I wouldn't use it.

You bet.  It will handle cranks well.  Depending on how you fish jerkbaits, it may work well too.  If you are deadsticking, slowly sweeping, and finessing jerks, this rod should shine.

Where the mod-fast action won't be the best for jerks is if you plan on ripping your bait with hard jerks of the rod: the rod will take a lot of the action out of the lure.