To which doctor should i consult for lowsodium level around 105?

Go to ER: Although I doubt your sodium level is 105, if it is very low it needs immediate attention. Please go to the hospital emergency room.

Severely low: It really depends on what the cause of your low sodium is, but I'm surprised if you are not in a hospital with a sodium of 105. That is exceptionally low. A nephrologist may be able to better sort out the cause or causes and how to best correct this in a fashion so as not to cause your problems.

Go to ER: If your sodium level is 105, you need to be seen in the ER now.