Hi , I struggling at triggering of mosfet in proteus simulation . Without gate supply mosfet turned on .I dont know whether to add any component please let me know if you know. I attached simulation image .

 

It is not clear as to what you intend this circuit to do.
Firstly, if you press the switch, then 12V is applied to the opto's diode and will blow that instantly.
Again the MOSFET is connected across 200V and ground. If it turns on, then it will also blow instantly as it shorts 200V to ground.
MOSFET's gate has a very high input impedance and should not be left open. A 10K resistor to ground (source) is normal.

 

You need a circuit like this..
PS your bulb will blow up if its not 200v rated!

 

Hi finally i triggered mosfet thank you all.