I know 200's are Rural Metro Fire but they have a bunch of stations so the 200's may be subdivided further to indicate which station.
https://www.ruralmetrofire.com/stations-a-service-areas-eastern-tennessee.html
RMFD Station # 10 - 9746 Parkside Dr, Knoxville TN
RMFD Station # 11 - 160 Campbell Station Rd, Knoxville TN
RMFD Station # 15 - 1012 Summerwood Dr, Knoxville TN
RMFD Station # 16 - 10208 Bluegrass Rd, Knoxville TN
RMFD Station # 17 - 1332 Timbergrove Rd, Knoxville TN
RMFD Station # 25 - 8414 Old Rutledge Pke, Mascot TN
RMFD Station # 26 - 8707 Strawberry Plains Pike, Knoxville TN
RMFD Station # 27 - 5525 South National Dr, Knoxville TN
RMFD Station # 28 - 3111 Old Maryville Pike, Knoxville TN
RMFD Station # 30 - 7401 Lena Ln, Knoxville TN
RMFD Station # 31 - 7201 Old Clinton Pike, Knoxville TN
RMFD Station # 33 - 9337 Davis Rd, Corryton TN
RMFD Station # 34 - 7309 Tazewell Pike, Gibbs TN
And 400's are Karns Volunteer Fire Dept.
Karns Volunteer Fire Department - Welcome to our site!
And 700's are Rural Metro EMS.
Ambulance Services - Community Ambulance Services, Neonatal Transportation, Wheelchair Transportation - Rural/Metro South
Here are Knoxville Fire Depts. They are on the trunking system but could also may be on that freq as a backup.
City of Knoxville - Fire Stations
Downtown Headquarters, 600 Summit Hill Dr, Knoxville TN
KFD Station # 3 - 204 E. Baxter Ave, Knoxville TN
KFD Station # 4 - 2300 Linden Ave, Knoxville TN
KFD Station # 5 - 419 Arthur Street, Knoxville TN
KFD Station # 6 - 3925 Holston Drive, Knoxville TN
KFD Station # 7 - 1216 New York Ave, Knoxville TN
KFD Station # 9 - 1625 Highland Ave, Knoxville TN
KFD Station # 10 - 2911 Sevier Ave, Knoxville TN
KFD Station # 11 - 2600 Whittle Springs Rd, Knoxville TN
KFD Station # 12 - 4620 Old Kingston Pike, Knoxville TN
KFD Station # 13 - 4701 Chapman Highway, Knoxville TN
KFD Station # 14 - 5400 Central Ave, Knoxville TN
KFD Station # 15 - 5301 Jacksboro Pike, Knoxville TN
KFD Station # 16 - 5102 Asheville Highway, Knoxville TN
KFD Station # 17 - 4804 Oak Ridge Highway, Knoxville TN
KFD Station # 18 - 610 Weisgarber Rd, Knoxville TN
KFD Station # 19 - 6328 Chapman Highway, Knoxville TN
KFD Station # 20 - 200 Portsmouth Rd, Knoxville TN
KFD Station # 21 - 245 Perimeter Park, Knoxville TN
And Knox County Fire Prevention Bureau
Fire Prevention Bureau - Knox County Tennessee
And Knoxville Volunteer Rescue Squad
Knoxville Volunteer Emergency Rescue Squad | Knoxville Volunteer Emergency Rescue Squad
And Claxton Volunteer Fire Dept is dispatched by Anderson Co but could also be dispatched by Knox Co if I'm thinking right.
First Call Ambulance Service was in Knox Co but I'm not sure now.
http://www.firstcall-ambulance.com/knoxville-tn.php
Pro Med EMS was in Knox Co too but again I'm not sure now.
http://promedems.org/
These are all a list of possibles that I know of. Sometimes you can look on their websites and see the numbers on the fire engines or on the actual truck. Hope this helps you some.