Q. Is Jawa Standard a good bike for 6ft person ?

Actually jawa is good for all people including short and TALL.. the seat height is pretty low which makes it easy to ride for short riders.. Its pretty good for tall riders as well because of the riding position and the handlebar position.. The handlebar is situated at a pretty good height giving the rider GREAT legroom so that handlebar won't be hitting your knees when taking tight turns.So my answer is it's a good bike for 6ft and above riders also

As single rider yes, it can accommodate 6ft person. Not with pillion.

No.its ok no problum i am 5.5