Hello Raju_P,
Thanks for asking the Apple Support Communities for help with deleting apps.
Please verify you are deleting as per this help article: Delete apps from iPad - Apple Support
If you still have issues, do you have Screen Time is enabled? Specifically check if the option in Settings > Screen Time > Content > Privacy Restrictions > iTunes & App Store Purchases > Deleting Apps is set to "Don’t Allow": Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support
They may also be reappearing if you have automatic downloads enabled and are downloading them on another device signed in with the same Apple ID: Manage App Store purchases, subscriptions, settings, and restrictions on iPad - Apple Support
"Automatically download apps purchased on your other Apple devices: Below Automatic Downloads, turn on Apps."
Thanks and have a wonderful day.