Starting with 9, CUCM and IM&P are tightly coupled so the same version applies to both, you cannot deviate from that. For IOS, Cisco is always flexible. There has been always confusion that there is a linkage with IOS and CUCM. Cisco tests certain combinations since it is not feasible to test every single IOS version. sccp based resources will show a version number and unless your IOS is really old even if the version doesn't match, we have customers where registration works fine. TAC cannot refuse support unless it is proven there is a bug or issue with the IOS code and the IOS code is under valid support.
Having said all that you can use this link even though 9.1 isn't listed but you can see 10 for example and use that IOS version
Cisco Collaboration Systems Release Summary Matrix for IP Telephony - Cisco
