rated 15 (uk)
http://www.fox.co.uk/terminator-dark-fate
most recent R rated SF stuff is 15 in uk - BR2049, Alien Covenant, Fury Road, Logan, ITs etc. back in the 80s/90s R rated movies regularly got 18 in uk but it has to be very extreme to get an 18 now (last year Halloween got it and Once Upon A Time in Hollywood has been rated 18 like most of Tarantinos)
T:DF is the first non 12A rated Terminator since T2! (T1 was 18, T2 was 15, T3 was a 12 even though it was rated R which must be the only time that's happened as R is always either 15 or 18 in uk with PG13 being equivalent to 12A or in some cases 15 like AvP, Die Hard 4.0)