Hello bnsrini,
Thanks for visiting Apple Support Communities. We understand that you're not able to share a photo from the Photos app to some apps, but can if you're using the app itself. If you haven't already, restart your iPhone as restarting can resolve many odd issues: Restart your iPhone
Also be sure your software and apps are updated. If updates are needed, back up your iPhone first:
How to back up your iPhone, iPad, and iPod touch
Update your iPhone, iPad, or iPod touch
How to manually update apps on your Apple device
After restarting and updating, check to see if the issue continues. Just in case, more information on sharing can be found here: Share photos and videos on iPhone
Let us know how it goes.
Take care.