Flight VTBS - HKJK via route BONV1G BONVO M502 LALIT P762 KAT G465 MLE L756 CLAVA UM432 EGLOM UT386 KESOM UL303 IBROM IBRO2C.
Step Climbs on, whole other flight it suggested correctly even flightlevels, except in Seychelles FIR (FSSS) it suggested CLAVA/FL350 and IPVIG/FL370 which would have been okay if north-south semi rules, but FSSS also follows west-east so should have been suggesting even levels.
Without access to the Seychelles AIP the assigned airway cruise table would indicate ODD flight levels on that segment, so would appear correct. Semi-circular rule may not apply.
Steve.
You might be correct in this. As actually, while yeah that Seychelles AIP is not available for free… I took some reference from Mumbai FIR (next towards east) and already it has actually airway L756 RULSA - CLAVA following rules “south odd, north even”… so SimBrief propably should have suggested odd level already from RULSA, while it suggested to keep even level. 
https://aim-india.aai.aero/eaip/eaip-v2-04-2026/index-en-GB.html
According to the AIP is EVEN level. The level is restricted by navdata on the L756 segment, however this restriction may not apply:
3. On this ATS route only FL280 and F290 are available for westbound and eastbound flights respectively, higher flight levels are available only in coordination with MumbaiOCC. These restrictions are not applicable to fans1a data link capable flights.
