Tds refund from minor 26 as

Please contact your TDS Ao as well as your Son's Jurisdiction AO and explain the case. Your sons income should be clubbed  with your income.

firstly u have to check if ur son's income is eligible for TDS deduction....u can submit form 15G or H ( check it out) if he is not elegible to pay taxes...and the bank wont deduct ur sons TDS

if his TDS is deducted, he can claim deduction as he has interest income from the bank...and u can use it when u are clubbing his income with yours.

i think the 1st step is better.. submit 15G and they wont deduct TDS

Ask bank to Rectify TDS Return. Changing of PAN number may be difficult in TDS return.

Better to go to TDS AO of ur Son's jurisdiction ward AO.  Ao might transfer TDS credit from Son's PAN no to ur PAN. 

You should file a return taking that int income and  that tax credit with same BSR code and challan. Dont E verify or send ITR-V to CPC untill TDS credit is transfered to ur PAN