@Aritraaa 

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

If the issue is still the same, please help confirm the following information. 
1. Does the camera show offline on the Tapo app when your phone is connected to the same Wi-Fi as the camera?

2. The model number Wi-Fi router and your network topology:
e.g. ISP Spectrum-wireless router<Wireless> tapo camera

3. Please go to the camera's Device Settings>Device Info page when it's working, tap the Wi-Fi icon, and send me a picture of the signal strength value.

4. Send me(Solla-topee) the MAC address of the problematic Tapo C210 via a private message.
 

5. You can try to enable the Auto Reboot feature on the camera's Device Settings>Reboot Camera page and check if it helps.

Best Regards