@pranitpatharde First thing we need to check is if there is a software problem. Follow this [link|https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.hardreset.info/devices/xiaomi/xiaomi-redmi-note-5/codes/&ved=2ahUKEwiZ07-L5OWAAxVCyDgGHRLaCvEQFnoECB4QAQ&usg=AOvVaw1cPbvtnk38mrLbUdcdWdo3|guide|new_window=true] to access the diagnostics menu, and select Vibration motor.
If it works in the menu, it's a software issue.
If it does not, the vibration motor needs replacing, following this [link|https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://m.youtube.com/watch%3Fv%3D9hpbxRQpz2w&ved=2ahUKEwjV4b-y5OWAAxXGzzgGHY2oDMsQwqsBegQIDRAG&usg=AOvVaw2h1_KO1aSo65TDy_MqJUAa|guide|new_window=true].