I would like to have 24 infrared led. The main concept of this circuit is to blink for the 24 led.
I will be using 12V. Is it possible guys?
If not possible, any idea to let 24 infrared led to blink?

 

How much current do want in each LED?
The circuit you show will run the LED at about 100mA and the maximum current from the '555 is 200mA so it going to be able to drive 24 LEDs at that current. You would need something to switch the higher current, probably the best choice would be a MOSFET.