To have a repeater coordinated, you must first provide the coordinator for the band on which you wish to place the repeater with basic information about your proposed system. This should include the following.
Geographical latitude and longitude
Amateur or group that will be the "Holder of the Coordination"
Proposed height above average terrain 
Proposed height above sea level.
Call sign that will be used to identify the repeater.
Any other useful information about the proposed repeater.
The coordinator will do a search of the entire band to see if there is a frequency available that meets good amateur practice with regard to spacing. In other words, the users of the proposed repeater or the repeater transmitter itself cannot cause harmful interference with an existing repeater and, of course, you do not want to invest the time and expense of putting a repeater on the air if it is going to be plagued with interference from existing systems.
If a frequency is found which is usable, the coordinator must then submit a notice of proposed coordination to NFCC recognized coordinators in any adjacent state that has a boundary within 120 miles of the proposed repeater location. These coordinators must concur with or object to the proposed coordination. Since repeater signals do not stop at state lines, we must cooperate with the adjacent states in order to issue valid coordinations. They will likewise cooperate with us.
Once concurrence is received from the adjacent states, the applicant will be notified that the coordination will be granted.
We will issue a coordination to anyone properly licensed to operate the proposed repeater provided there is a frequency available for use.
Membership in the Indiana Repeater Council is not required to utilize our coordination services.
We serve members and non-members equally.
The Indiana Repeater Council does not charge for its services.
 Average terrain is the average altitude for a 10-mile radius from your site in all directions.
If your antenna structure is on very flat land, your height above average terrain (HAAT) will be about the same as your antenna height above ground.
If your antenna structure is on a hill, your HAAT will be somewhat more than your antenna height above ground.
If your antenna structure is in a low spot, HAAT will be somewhat less than your antenna height above ground.
 Refers to height above sea level at the top of antenna. (Height above sea level at ground + antenna structure height.
 Power applied to the base of antenna multiplied by antenna gain factor.