Does French have the sound [tɕ] as in "question", or is it still [t]? It really sounds like [tɕ] in some materials, but according to Wikipedia, French does not have this sound.
I've never heard the sound [ɕ] in French aside from people with pronunciation defect (chuintement), e.g. caused by braces. I'm mostly familiar with French from France but I haven't heard it in other regional variants either.
EDIT: the question changed to ask about whether there is [tɕõ] in words like "question". In standard French from France, this is definitely not the right sound — it would be [tjõ]. In Canadian French, it could be [t͡sjõ]. In informal speech in both places, it could become [sjõ]. I understand how [t͡sjõ] could be heard as [tɕõ] — the difference is subtle... If the s assimilates into the j then you have something that sounds a bit like ɕ though it would remain interpreted by a native speaker as [sj].
I should also clarify that it probably does happen and does not impede comprehension, e.g. I have heard a few native Japanese speakers do a complete assimilation and pronounce "question" in French as [kɛstʃõ], I'm guessing because they hear [sjõ] as indistinguishable from [ʃõ] or have trouble reproducing that sound, or because they had learned pronunciation using Japanese syllabaries. It is understandable, just wouldn't be considered standard or correct pronunciation.