Context : Long-term precise Doppler measurements with the CORALIE spectrograph revealed the presence of two massive companions to the solar-type star HD202206 .
Although the three-body fit of the system is unstable , it was shown that a 5:1 mean motion resonance exists close to the best fit , where the system is stable .
It was also hinted that stable solutions with a wide range of mutual inclinations and low O-C were possible .

Aims : We present here an extensive dynamical study of the HD202206 system aiming at constraining the inclinations of the two known companions , from which we derive possible ranges of value for the companion masses .

Methods : We consider each inclination and one of the longitude of ascending node as free parameters .
For any chosen triplet of these parameters , we compute a new fit .
Then we study the long term stability in a small ( in terms of O-C ) neighborhood using Laskar ’ s frequency map analysis .
We also introduce a numerical method based on frequency analysis to determine the center of libration mode inside a mean motion resonance .

Results : We find that acceptable coplanar configurations ( with low \chi ^ { 2 } stable orbits ) are limited to inclinations to the line of sight between 30 \degr and 90 \degr .
This limits the masses of both companions to roughly twice the minimum : m _ { b } \in [ 16.6 M _ { Jup } ; 33.5 M _ { Jup } ] and m _ { c } \in [ 2.2 M _ { Jup } ; 4.4 M _ { Jup } ] .
Non coplanar configurations are possible for a wide range of mutual inclinations from 0 \degr to 90 \degr , although \Delta \Omega = 0 [ \pi ] configurations seem to be favored .
We also confirm the 5:1 mean motion resonance to be most likely .
In the coplanar edge-on case , we provide a very good stable solution in the resonance , whose \chi ^ { 2 } does not differ significantly from the best fit .
Using our method to determine the center of libration , we further refine this solution to obtain an orbit with a very low amplitude of libration , as we expect dissipative effects to have dampened the libration .

Conclusions :