Procr should be in NR250, and not have any DSP.
But, in that case, so long as NR1 can talk to 250 and 250 can talk to 2-5, you'd get the same result and fish DSP in 2-5 if DSP in NR1 was down.
Procr being in NR1 has very little to do with it. That just means h323 phones registering to it inherit NR1 if their IPs are defined in the network map as belonging to other regions.
You can still have extra regions with nothing in them. DSP selection is ultimately based on hop count - that's why you can have many intervening regions between two NRs.
Practical example;
Customer has national presence. SIP trunks come into data center east and data center west. Call them NR 10 and 20.
All agents are at branch sites with no gateways.
All calls are recorded.
All calls delivered to DCwest are for west sites. Same for east. Say the west branches are NR 11-19 and east are 21-29
I want all my west people to use west DC DSP only, until they run out, or are down, then they can use east. Same rule for the east guys.
Now sure, based on the calls coming in the west sbc, with a media IP in the map in the west DC region, thru to agents in those other spoke regions would pick west DSP first. We wouldn't have to tweak the NRs much to accomplish that.
But what about when west agent calls west supervisor and conferences another west person - where does the DSP come from? Say 3 callers conference each other within NR11.
All NRs are direct to 250.
I make a NR 249 with nothing in it, also direct to 250, and 10 and 20.
11 reaches 10 thru 250
11 reaches 20 thru 250 and 249
21 reaches 10 thru 250 and 249
21 reaches 20 thru 250
Had I just made every NR hang off 250, then when 3 people conference within NR11 needing a DSP, CM would look '11 to 250 and all gateways are then equally distant. Let me do some quick math about which gateway is least used right now, I'll pick that'.
In my example with 2 intervening regions, 11 asking for DSP would have CM say 'well, this guy knows how to reach 10 and 20 where the dsps are at, but 11 to 10 is 2 hops - 11 to 250 to 10. 11 to 20 is 3 hops - 11 to 250 to 249 to 20. I'm going to math out the freest DSP in NR 10 before I offer this 3 way call of 3 phones in NR11 anything out of NR20. NR10 would need to be out or down before this call could potentially take NR20.
So, back to your example, as long as your network region matrices aren't blank between NR1 and 2-5 - to say, if NR1 has some defined path to NRs 2-5 and a codec set defined, CM will try to find a way.
There are all sorts of designs that don't have CM controlled H248 gateways on site. Drop a cheap audiocodes mp112 or a IPO as a 3rd point of SIP registration. It can all still leverage core CM network design despite not having local h248 cm managed DSP.