In Samsung A16 5g (A166P) There is no option in settings for enabling VOLTE for BSNL, If any Samsung A16 5g user experiencing same issue please share and my request to samsung officials to look into this matter and make this feature available for dev...
It does support 4g and u can see 4g icon, other devices show volte for bsnl even other samsung devices have settings to enable volte for bsnl but not this device
