1.You can file complaint against public information officer without going for first appeal or even after going to first appeal under Sec.18 of RTI Act praying for penalty, recommendation of disciplinary action against authority. But IC can not grant your prayers for getting directions for information.
Only in rarest of the rare cases, IC, may impose penalties .
The complaint has no prescribed format and can be filed within a reasonable time.
2.If you want information, you have to go for second appeal before Information commission only after first appeal and FAA orders. You can seek all remedies including information under Sec.19. including direction to PIO for providing information, imposing penalty, recommendation for disciplinary action and compensation (all four remedies possible under RTI Act)
Some thing that filing complaint may hasten/speed up FAA orders for information. Both complaint and appeal can be filed separately or combined.