My relative is under the charges of 399,402,21-b(a) arrested on 12 jan

They are 5 persons who got caught together in a car and my relative has stick (dnda) in his hand according to police . They did not commit any dacoite nor ther attempt they are arrested on the behalf of planning . He has no previous criminal record and he is currenty a student also . So i really want to know that how serious this matter is and us there any chance that ge can get out of this situation by anything. Because some lawyers are saying that in this crime he can even get life imprisonment. So i just want to know that what is tha maximum or minmum consequences in this case