Question

if value of planck constant is too high what will be the effect

Answer 1

These questions can be very interesting because of how far reaching a single change can be.
However if we try to change one constant (I'm going to chose the speed of light for simplicity of the argument) then other constants have to follow.
For instance if the speed of light were to change, then for the equation c = 1/√ε0μ0 to remain valid then we must chose which of the other constants to alter with it. Each of these other constants may have equations (that we may or may not know of) which may result in other constants changing.
See fine tuned universe.
Ultimately nobody knows if it is even possible for any of the paramaters to be altered or if so how many. This is what Einstein was reffering to when he said:
"Did God have any choice in making the universe?"
For all we know there may be an infinite number of universes in the multiverse each with its own altered set of physical laws.

To actually answer the question-
Planck's constant relates to the quantum mechanics and the quantized universe. So increasing planks constant would basically increase the size at which quantum effects are noticable. (It is really tiny now which is what makes it so difficult to see quantum effects on a smale scale.)
Altering this would change many things on an atomic scale and would even affect how the sun shines.
Maths:
lambda = h/p
The wavelenth of an object is equal to plancks constant times its momentum (momentum is just mass times velocity (p=mv)).
To get good interentings quantum effects the wavelength should be at least (around) the size of the object and the object should be traveling fast enough to get somewhere (you cant just say p=0).
If plancks constant were large enough that quantum effects could be observerd with tennis balls and trains the wold would be a very different place with golf balls quantum tunneling through walls and cars being diffracted when driving through a forest, visible light as we know it wouldn't work and im not sure if matter would hold itself together properly.