Thank you for your kind response, There is no issue found in the diagnostic, it is "Normal". Also I have followed the article and checked the charger, still it works fine. Also the issue remains same if I use it in battery without plugging in to charger, battery health is precisely good it is giving up to 8 hours of backup.
I could have already visited the apple service centre but unfortunately the service centre is far away from my town and due to Covid-19 it is not possible to travel all the way there.
I am very hope less now. I am not sure what could be the issue here with the hardware also have tried to install the OS to a external HD to check whether it is something to do with the ssd but still no luck. What could be possible solution into it, besides visiting the centre if you could suggest it would be great help. Thank you.