@AtanuMondal 

Hi,
You can refer to the link below to troubleshoot if the Tapo Camera has an unstable issue.
What should I do if my Tapo smart camera keeps losing connection or going Offline?
 

If the problem remains, please help confirm the following information for further analysis.
1. Please check the LED status on the Tapo C210 when it is offline: Red/ Flashing Green/ Solid Green etc.

2. Please check the Wi-Fi Signal Strength of the C210 on the Tapo app.

3. Is your phone using other Wi-Fi networks/mobile data when the Tapo C210 shows offline on the Tapo app? Or does the camera show offline on the Tapo app even if your phone is connected to the same Wi-Fi as the camera?

4. Please describe your network diagram, such as the Internet--wireless router)))Tapo camera. 
What's the model number of your router? Do you have a stable connection when connecting to the router's Wi-Fi?

5. You can try to reset the C210 to factory default settings, connect it to a different Wi-Fi network, such as a hotspot Wi-Fi from your phone, and then check if it will work fine.

Best Regards