Fleming's right hand rule: Fleming's right-hand rule gives the direction in which current flows.The right hand is held with the thumb, the index finger and the middle finger mutually perpendicular to one other. The thumb is pointed in the direction of motion of the conductor relative to the magnetic field, the first finger is pointed in the direction of the magnetic field. Then, the second finger represents the direction of induced current within the conductor. 

Lenz's Law: It states that the direction of an induced current is such that it opposses the cause that has induced it. It is the consequence of the law of conservation of energy. 

Direction of induced current given by both the laws must be the same but obviously, both the laws are not the same.

Hence, Assertion is true but Reason is false