What is the time-in-service remaining requirement for E6?

I am an army reserve (USAR) TPU NCO with a little under a year left until I ETS. I was picked up for E6 but told the orders would not be published because I needed to reenlist so that I had 36 months time-in-service (TIS) remaining from the promotion date. I did some digging, and as far as I can tell, the TIS remaining required for E6 has never been 36 months. It was 12 months for USAR TPU soldiers in the 2017 version of AR 600-8-19 (see 3-32), but it was removed completely in the current, 2019 version of the AR (see 3-33). Although, the TIS remaining requirement was and still is 36 months for SFC and above (senior/centralized promotions), so maybe that is where the individual who told me this got their information from? Am I correct that there is no minimum TIS remaining requirement for E6, or that it is only 12 months? If not, can someone point me to where in a reg it says 36 months? Thank you!