Your priority date must be current in order to file I-485 concurrently with I-140. Priority dates for India in EB-2 are backlogged so that it is unlikely that your date is current. Your son must have maintained his status since his last lawful entry in order to be eligible for adjustment.
The answer provided here is general in nature and does not take into account other factors that may need to be reviewed for a more precise answer. You should consult with an immigration attorney before taking any action. The answer here is not intended to create an attorney-client relationship.