Hello Amardeep. If your Windows 11 laptop is showing the time zone you do not want it to show, for example, China instead of India, even after resetting it, then there is typically some sort of VPN (virtual private network) interference and/or location service settings. When "Set time zone automatically" is enabled in Windows, Windows determines your time zone using your IP address and location services.
If you're using a VPN, your traffic may be routed through another country (e.g. China) and Windows may attribute (wrongly) the wrong time zone based on that. To remedy your problem, go to the Settings > Time & Language > Date & Time. Toggle "Set time zone automatically" off. Using the time zone drop-down, select (UTC+05:30) Chennai, Kolkata, Mumbai, New Delhi.
In addition, if you intend for Windows to find your actual location, you should disable/reconfigure your VPN.
Best regards,