Can anyone please send me the code for counting pulses using timer 0 as counter in 'C'language.
That is not equivalent to the assembly code. For starters, you are not configuring the timer. Look back at your assembly code for TMOD.
No i have configured the timer as TMOD=0x25;
I forgot to write it. In main(), my first instruction is TMOD=0x25;
Are you saying that you typed in the code when posting?
Are you one of the few who have managed to get a computer without any copy/paste function?
How will we know what other information you forgot to write when "duplicating" the code?
"In main(), my first instruction is TMOD=0x25;"
OK then, we'll just assume that's true. If you want the counter registers to count, why do you continually zero them?