There is no need to file an appeal when you are satisfied with the order/ judgment passed in your favour, I concur with the opinion and advise of learned senior experts Mr. T Kalaiselvan and Mr. Bhartesh Goyal ji.
When you are not aggrieved by the order passed what do you intend to prove from the "unexhibited" document and why so?
Key difference may be questioned before your tutor/ coach/ professor.
You have stated in the facts posted, inter alia, that, "Can unexhibited documents (which was not exhibited in the family court) that were obtained through RTI be accepted and taken into account in the high court?" is contradictory to your further statement, inter alia, that, "And also, if I am satisfied with the decision in my maintenance case, should I go for an appeal or revision?" which make the facts as academic / hypothetical and not a real story.