Hi @Haider_ali,
What version of AE are you using?
What are your system specs including GPU?
How big is your model?
Can you try turning on Adaptive Resolution?
Lastly, can you turn open up the Renderer Options and lower the Renderer and Shadow settings down to around 8 and 3?
If you could send me the model so I can try on my end that would be helpful as well.
Thank you,