The elevation depends on the latitude of the location on Earth. For example, at 10° latitude, the elevation of the geostationnary satellite is about 78.25°. At 30° latitude, the elevation of the geostationnary satellite is about 55°. Etc.

Thank you Serge, for replying .

Have you got any reference for that can help? 

no reference ... I performed the calculus by myself.

It's only a problem of spherical geometry, considering the position of the geostationnary satellite (whatever the used band), and the position of the user on ground.

The only impact of the used band (Ku in your case) is the lowest usable elevation.