Hi and welcome to Just Answer!
Do I need to file a tax return for him?
If yes do I need to include the money he got from SSI?
Needs based SSI benefits - Supplemental Security Income are not taxable.
Social security benefits – paid because of earning record - might be partly taxable if the total income is above $25,000 – because that is not a case for your son – that would not be taxable.
So your son is not required to file a tax return because his earning is less than $5700 and he has no other taxable income.
You may want to file his tax return if there are any income tax withheld and you want to get them back.
Let me know if you need any help or clarification.
Thanks there were no Fed Inc tax witheld have a good day