SSI is not the same as Social Security retirement benefits. SSI is Supplemental Security Income. They both come from the Social Security Administration, but they are two different programs.
SSI is not taxable. You do not get any kind of 1099 form for it, and you do not report it on your tax return.
If you received Social Security benefits you should have gotten a Form SSA-1099, not 1099-R. Those are two different kinds of forms, and you enter them in different places in TurboTax. To enter your SSA-1099, type ssa-1099 in the Search box, then click the link that says "Jump to ssa-1099."
Form 1099-R is for pensions, IRA distributions, and other kinds of retirement income, but not for Social Security or SSI.
There is no SSA 1099R form. You get a SSA-1099 from Social Security for SS or SSDI. You don't get a form for ssi supplemental income and don't need to report it.
If you are trying to enter a SSA-1099 it sounds like you are in the wrong spot. It doesn't go under retirement 1099R.
Enter a SSA-1099, SSA-1099-SM or RRB-1099 under
Federal Taxes on the left side or top
Wages and Income
Then scroll down to Retirement Plans and Social Security
Then the second line - Social Security (SSA-1099. RRB-1099) - click the Start or Revisit button