If it's a standard 1099-R using the official IRS form, the Payer's TIN is right under the Payer's name and address. This is the most common situation. However, brokers/financial institutions may use their own proprietary form for their 1099's instead of the IRS standard 1099-R. If it's a non-standard form, look it over carefully. It may not call it a TIN. It may label it as the Payer's EIN or "tax number", etc.
In either case, though, it should only be 9 numeric digits, but no letters. Is it possible that you are looking at an account or reference number instead? But if the Payer TIN does include a letter, please contact the sender of the 1099-R for clarification. You can also try just omitting that last letter g.
