@arnavgarud you want to treat this just like you treat any other water damaged device.
For now you want to stop continuing to try to charge, sync or otherwise use your phone. This potentially can make a bad situation worse. This may further damage your phone.
The very first step you want to take, is to disassemble your phone. Use these guides [[Topic:Xiaomi Redmi Note 6 Pro]] as well as the ones [https://www.nadiemellamagallina.com/en/manuales/smartphones-1/xiaomi-191/xiaomi-redmi-note-6-pro-880/|from here] to help you disassemble your phone. Remove the main board as well as the charging board.Take a careful and close look at all components and connectors. Look for major corrosion, evaluate the pins in the connectors etc,. Take a look at all connectors as well as cable ends. You will have to remove all the EMI shields. If you do not remove the shields, you are not cleaning the board. Once you got the gross contamination cleaned, use 90%+ isopropyl alcohol and clean your parts some more.
For a proper cleaning, use [guide|5825|this guide.] It was written for an Apple iPhone 3G but all the points are still pertinent to your phone as well. I can not stress the importance of a good cleaning enough, so do it over and over while replacing the alcohol after each cleaning. Do not use compressed air for the cleaning since that can drive liquid as well as corrosion particles into areas that will cause trouble later on. The importance here is the cleaning. It would of course be best to get it professionally cleaned.
Do not forget to replace the battery. This is a must and not an option. It will fail if you do not take care of it now. After that, reassemble your phone and re-evaluate. For as long as you have not cleaned your board and replaced the battery, everything is just a guess. Keep in mind that water damage is the hardest to troubleshoot and to repair.
While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.