if i play bastard on maester can i add chain on it from maester path agenda (agenda do put in play an chain attachment)?

Since the chain is put into play from the agenda rather than played on the character, it should be possible.

No, cannot is an absolute term in this game. Bastard destroys maesters

Khudzlin is correct.

"Cannot" is absolute, but Bastard says you cannot play attachments on the character. "Play" is specifically defined in this game as the game effect/action of paying the card's gold cost (actual or modified) while you are the active player in Marshaling to take the card out of your hand and put it into play. That is what Bastard stops you from doing: playing attachments from your hand onto that character while you are the active player in Marshaling.

But if you are using a card effect to bring a card into play at any other time, by any other means, for the cost of the effect, not the cost of the card, you are "putting the card into play." The "cannot" stipulation on Bastard does not stop you from doing this. So you can attach cards to a card with Bastard using card effects (like the Maester Agenda), just not from your hand as the active player in Marshaling.

So yeah, "cannot" is absolute, but the difference between "play" and "put into play" makes "cannot play attachments" less than a perfect solution against Maesters and their chains.