How many downloads a mod has to be?

There is no specific number of downloads required. It's a case by case by case decision. As the suggest page says it can't be added then it can't be added and you can try suggesting the mod sometime later.

Quote from FilosZ

if I want to download the modpack, the mod is included or not?

Yes, Aternos provides the modpacks 1:1 as provided by the modpack creator.

Quote from FilosZ

if it is, why it is not downloadable about himself?

Aternos doesn't add every mod in available modpacks.

hello I want to put a mod called MiniaTuria but it would not be possible to integrate it

Quote from elsebitas

hello I want to put a mod called MiniaTuria but it would not be possible to integrate it

what?