But when Timer 2 Enables in main program (PIE1.TMR2IE = 1) ,both of two interrupts(cnt and cnt2) get incremented ...why ?/
Initialization of Registers are like this..
Most likely the other interrupt is pending and actioned as soon as the first one finishes. Try removing the 'else if' and replacing it with 'if' so that both can be processed in the same pass of the ISR. At the moment, both interrupts can occur but you exclude processing TMR2 if TMR1 is also active.