Hi Gayan,
I have also simulated your circuit using a continuous input square signal of 38KHz at 4.8V output voltage from the simulated IR-receiver which is done using a function generator.
The output signal follows exactly the input signal as you can see by the scope screenshot.
Extensive simulation shows the timer circuit runs as an astable multivibrator if the reset input voltage exceeds 1V (pretty precisely).
With the base of T2 floating this will be the case causing 1.3V at the collector which connects to the reset pin of the timer IC, hence not resetting it!
So you must force the base of T2 high enough to pull the reset pin low if there is no reception of the IR-receiver.
If you're using a series resistor with the power (+V) of the receiver just short it out and check what's going on.
Scope presentation: channel1 (yellow) -> input signal from receiver, channel2 (blue) -> signal at the base of T1, channel3 (violet) -> collector voltage of T1, channel4 (green) -> not used.
Next time I want to read "success".
Kind regards
Boncu