Hello Rahul-gandham,
Thank you for posting in the Apple Support Communities.
We understand you need access to cellular data when away from Wi-Fi. We'll be glad to assist.
Take a look at the settings for your carrier on your iPhone. Follow this: Check the cellular data usage on your iPhone and iPad
Verify you have cellular data on for your apps you'd like to use.
Please complete these steps: If you see No Service or Searching on your iPhone or iPad
The troubleshooting here can help with connecting your iPhone to the cellular network.
We look forward to hearing back from you with the result.
Have a great day.