The Battle of Oriskany was part of the Siege of Ft Stanwix. St Leger's  command consisted of the following elements when they left Oswego on July 25
King's Royal Regiment of New York  133 (Sir John Johnson)
Rangers from the Indian Deartment  67, ( Col John Butler)
Canadians  50 (Capt Rene de rouville0
8th regiment   100 ( lt harry bird )
34th Regiment  100 (Capt  Richard Lernoult)
Hesse Hanau  jaegers  50  ( 1st lt Jacob hildebrand
2 Six Pouners  2 Coehorns
Indian dept Officers  15(Col Daniel Claus, Capt Wm Johnson)
Senecas  200
Cayugas  200
Mississaugas  150
Mohawks  400  ( Capt Joseh Brant)
Delewares   ?  
Total approximately 1,000
When Leger heard about the advance of Herkimer's column he sent the following force that actually fought Oriskanay
The light Company of the Royal Yorkers John Butler and 30 rangers, 200 Seneca Warriors under Sayenquerahta and 100 Mohawks under Brant.
During the battle a sorties of about 300 Rebels sortied from Ft Stanxix and weresuccessful in destroying the camps of those fighting at the battle.  This left the Insdians with prectically nothing as they lost ther blankets and food.Coupled with the fact that the artillery was not capable of damaging the fort led to the abandonment of the siege Leger later claimed that one proper howitzer or naval mortar would have made a big difference
Source "Kings Men the Soldier Founders of Ontario" by Mary Beacock Fryer
"Sir John Johnson Loyalist Baronet" by Earle Thomas