My charger pin is not going in the charging port

@himanshu59930 start by measuring the AC adapters output voltage. If that is correct, check the pin on the adapter. Clean it of any debris check for deformitybor broken pins . If the adaptervis okay, check the DC in jack for any debris and deformity. After that, you will have to start disassembling your laptop and checking the DC in jack and the charging circuit on your computer. Your dc in jack maybe soldered to the motherboard or it may be connected via a cabe and plugged in on the motherboard.

To work on any circuits, You will need to find the schematic and component layout for your specific motherboard