Dependent

There is no way a six year old can provide for his own support so disregard that requirement.  If the Social Security benefits are the only income the child receives then they do not have to file a tax return and you do not enter his SS benefits on your tax return.

To be a Qualifying Child -

1. The child must be your son, daughter, stepchild, foster child, brother, sister, half brother, half sister, stepbrother, stepsister, or a descendant of any of them.
2. The child must be (a) under age 19 at the end of the year, (b) under age 24 at the end of the year and a full-time student or (c) any age and permanently and totally disabled.
3. The child must have lived with you for more than half of the year. Temporary absences while away at college are considered living with you.
4. The child must not have provided more than half of his or her own support for the year.
5. If the child meets the rules to be a qualifying child of more than one person, you must be the person entitled to claim the child as a qualifying child.
6. The child must be a U.S. citizen or U.S., Canada or Mexico resident for some portion of the year.
7. The child must be younger than you unless disabled.

Do not enter the SSA1099 for your child on your own tax return.   Someday if the child has other income  (after school job, etc.) and is filing a tax return, for that tax year he will need to include the SSA1099 on his own return.  Until then, it does not get entered anywhere.

You can still claim your child as a dependent.  The SS he is receiving does not disallow you from claiming him.   File a joint return with your spouse so that you get all the child-related credits for which you are eligible.

Your spouse's SS goes on the joint return.   But only his----not your child's.

Go to Federal> Wages & Income>>Retirement Plans and Social Security  (SSA1099 and 1099RRB) to enter your SSA1099.