I took rmd from 2 traditional iras. Originally bought in a bank and moved to funds over the years what is my cost basis? What I put in the bank ? Or last purchase?

[fanfare]

the entire amount is ordinary income.
There is no cost basis for IRAs, unless you elected to make your contributions non-deductible.

[fanfare · Accepted solution]

some states (most ?) will let you deduct your "basis" of undeducted contributions.
You must know how much you contributed to your IRAs over the years.

[VolvoGirl]

You don't enter any of that for a 1099R.  You don't report it as sales.  Just enter the 1099R.
The easiest way to get to the 1099-R entry screen is to simply search for 1099-R (upper- or lower-case, with or without the dash) in your TurboTax program and then click the "Jump to" link in the search results.

Enter a 1099R under
Federal Taxes on the left side
Wages & Income at the top

Then scroll way down to Retirement Plans and Social Security,
Then IRA, 401(k), Pension Plans (1099R) - click Start or Revisit

If you are filing a Joint return be sure to pick which person it is for.

If box 2a is zero or says unknown then leave it BLANK

After you enter the 1099R be sure to answer all the follow up questions on the next screens to determine how much is taxable or not. Go all the way to the end of the section. You have to enter it from the 1099R because there are codes on it you need to enter properly.