Thanks , I was reading this article : https://smartasset.com/retirement/a-guide-to-the-pro-rata-rule-and-roth-iras
where it says "This rule requires you to consider all your IRA accounts as a single entity when calculating taxes owed on a conversion. Essentially, if you have both pre-tax and after-tax contributions in your IRAs, the pro rata rule mandates that any conversion must include a proportional amount of both. " Hence i raised this question.
