Hi @renukabista
Here's the [https://dl.dell.com/content/manual19865617-inspiron-14-3000-service-manual.pdf?language=en-us|service manual] for the laptop.
Go to p.77 to view the procedure to remove/replace the power adapter port.
Initially, remove the battery from the laptop and then just disassemble the laptop only as far as to gain access to where the power port cable plugs into the motherboard. Then unplug the cable from the board and use a voltmeter and check if there's 19.5V DC when measuring between the red and black wires on the cable plug when the charger is connected to the power port.
If not then the port is faulty and will need to be replaced as it cannot be repaired.
Search online for [https://www.google.com/search?client=firefox-b-d&q=Dell+Vostro+14+3000+dc+in+jack|Dell Vostro 14 3000 dc in jack] to find suppliers that suit you best. (examples only)