Megaman (or Rockman in Japan) apparently draws several influence from Tokusatsu. I think these are the series that have inspired Rockman's conception in the first place:I think Megaman is most likely inspired by Metalder which was inspired by Kikaider. Why? Some of the robot masters in Megaman are almost based on Metalder but not all. Metalder was an android created to combat the evil Emperor Neros. Parallelisms would be Metalder's creator Dr. Ryouichiro Koga would resemble Dr. Light, Springer would resemble Rush and Emperor Neros as Dr. Wily being the scientist rival who seeks to conquer the world but he's WAY more evil. Emperor Neros is a cyborg. Some robot masters in Megaman that would be inspired from Metalder are Yamatoman, Gyroman, Napalmman and Shadowman. However I do see a Bioman resemblance too with Dr. Wily being a lighter version of Dr. Man. For Bioman I can't help but do this comparison of inspiration- Juuoh (Darkman Robots), Messerjuu (Tenguman, Storm Eagle), Psygorn (Fireman), Aquagaiger (Bubbleman) and Monster (Gutsman).
I think Janperson (termed as Asia's Robocop as he was created in honor of Robocop) also inspired Megaman except he fought against three evil organizations at once. I think the Neo Guild would inspire the robotic terrorists in Megaman but they didn't have much diverse enemies. Gun Gibson IMO suspiciously resembles Protoman/Blues and may have also inspired the creation of Axl in Megaman X7-8. Janperson also had an android friend that may have inspired Eddie of Megaman.