Time slows down on Jupiter because of higher gravity, but Hourclock(sand clock) run faster due to higher g. If I am correct than how?
You are right to state that a gravity-driven sand clock or hourglass will run fast on Jupiter because of its greater gravity and also that in jupiter's gravity well, all clocks will run slower that they would on earth. However, note that the speed with which an hourglass empties itself and the effect of gravity on the passage of time are two different things. They seem related in this context only because the hourglass requires gravity to work, and changing the force of gravity will change the run speed of the hourglass.
Note that there are other types of clock which do not require gravity to run (electronic cocks, clocks driven by coiled springs, etc.) and moving one of these from earth to jupiter will not cause it to speed up. But any clock, regardless of how it works, will slow down in a stronger gravity well.
Two additional notes: 1) the effect on the run speed of clocks due to gravity is, for objects the size of planets or even the Sun, small, and 2) Jupiter has no solid surface like what we've got here on earth!