My son is here on E2 visa, i have full costody of him.- He cant get a SSN, I have tried. And here its ask for his SSN all the time, what to do?

If you are going to claim him on your taxes, you must apply for an ITIN (Individual Taxpayer Identification Number) for him. IRS will not approve without his SSN or ITIN.  Here are the steps:

• In the TurboTax program,  leave the SSN space blank
• After completing the return, print out the forms. Write APPLIED in the dependent's SSN space.
• As TurboTax does not support the Form W-7, fill out the forms by following  W-7 and attach other required documentation
• Submit all forms and documents to the IRS Austin location in Texas.  (see Form W-7 instructions) 

Thanks.

What supporting doc. do I need to attach?

Here is the link:

https://www.irs.gov/pub/irs-pdf/iw7.pdf, page 3 under "Supporting Documentation Requirements"

@supot