when i play media either from TV or Music app on Macbook air. No media plays

What's the difference between now and previously?

Was the machine wiped in between?

Is the storage on the computer more than 85% full?

Are you using any cloud services for backup, or any optimization tools? Optimization tools actually break Macs.

And background processes you might be running could delay the appearance of the video.

This includes VPNs, other network traffic apps (such as frequent email checks), and connection to other devices in file sharing mode. Using sidecar with an iPhone or iPad can slow things down.

You can post a report from Etrecheck on this board to help us identify those processes and suggest solutions:

Etrecheck - the handy reporting tool for … - Apple Community

You may need to purchase or rent the show before it let you stream more than its trailer.

Any streaming files depend on being logged in to the service. Make sure you have the bandwidth to stream. The more devices sharing your WiFi, the harder that will be. Make sure you have a WPA2 or better security WiFi, or are directed routed to your modem.

Are you using the laptop's built-in display or an external display to view the content?

Unless the external display is compliant with HDCP DRM (High-bandwidth Digital Content Protection Digital Right's Management protocol......not your rights, but the movie industry's lockdown of content protection & restrictions), then such media may not be allowed to be displayed on that device. It is meant to prevent people from being able to make a copy of the content as it is being played.

Is the media actually stored on your computer?

Do you know where the original file stands?

Is it media you downloaded from the App Store?