Depends on company sop, by what altitude must you be stable and what is the maximum sink rate.
With a normal load, slight headwind on a 3deg gp at 6,5nm out blazing in at 190-200kts you're usually stable by 1000' if you are with flaps 5 and start getting the a/c dirty but it varies alot from time to time. If its a hot summer day with alot of thermal activity it gets more difficult. The 737 is not forgiving.