What is effect of friction on MA, VR and n​

The force that resists the motion of one surface relative to another with which it is in contact is called frictional force or friction. The value of friction depends on the nature of surface (rough or smooth), nature of material, and nature of motion (rolling or sliding), etc. Friction wastes the kinetic energy of a machine in the form of heat energy. Practically, machines are not frictionless. Therefore, friction reduces MA and efficiency of simple machines.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.