Because of that i want to save time instead of making two different posts. can i make one post and share the same topic on both Bitcointalk and Altcoinstalks?
Sure why not?!
If it's relevant to the forum/topic/subject/timing/audience, then post it on the other forum, it's not a big deal. But make sure, if you are using others posts, then add the source links or the proper credits. And if it's your own words, then adding the source wouldn't matter much, since it's yours fully, but add it just in case...
There are some exceptions though..
For example, you reply to
Person A with
Reply A at BTT
And on the other forum, you reply to the
same person with the
same reply.
That's unnecessary and is considered spam.
But if you posting translations work, like I did an hour ago. Then that's ok. The more than platform, the more the audience it reaches.