how to solve this i dont know any idea

You have created an After Effects Composition set to 45 frames per second.
You are now attempting to render that composition to a footage file format which does not support 45 frames per second.
AE can automatically change your ouput to work with the format you have selected but that may cause unwanted audio results in your rendered footage.

Is there a reason you have set your After Effects Composition to be 45fps? If not, I would suggest changing it to a more standard rate of 30fps which should be supported by the format you have chosen.

If you do need your output file to be at 45fps, then you will need to choose a different output format to render to.