Is Den-o character from the main season the same one in Decade
 

so i just started watching Den-o due to i wanted to watch the season after Kabuto due to the fact it was the next rider after the kabuto so is his character the same on in Decade help me out

Canonically, yes. If I recall, the Den-O that appeared in Decade is the canon Den-O.

However, the actor is not the same person.

well i under stand why i think due they could not get him and also to fit in the alternate time line of things

Yes, it is the canon one.

thought as much but i made another thread bout this but i troubled with how TV nihon made the last 3 episodes

Yup same kid. Decade takes place after Final Countdown. The last time that Ryutaro was still an adult. The kid from the Decade episodes (and Neo Generations film) played young Ryutaro in Ore Tanjou. They brought him back since he was just old enough to play the character in his own right. Canonically it is the same character. They deaged him thanks to some time travel business that was never quite explained.

awesome thanks oh did toei ever made the last 3 episode a 1 hour and 11 min episode

Which is, of course, Decade's fault :lol.