That's right, we currently do not have anybody for Tamil.
You can contact Patchou and ask if he add's you. But keep in mind that Patchou sometimes refuses to add dialects and languages which are almost not used. He does that to keep the filesize of Plus! small. I don't know what language Tamil is though so i can't say if Patchou would add it or not, ask him
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Keep in mind that the is not much time left before the release of Plus! 3.0. So if you are accepted as translators there is probally not enough time left for you to translate everything on Plus!, test it, etc. So the first release with Tamil language possibly included will be the one after 3.00.
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