Is there any synonyms to fruit beer, beermix or radler? Any other cool examples for these kind of beers?
I presume you want to know this so you can find good ones to try. Some (but not all) fruit beer falls into the style "Fruit/Vegetable Beer". The link below will take you to a list of beers in that style, ranked by number of reviews (so popularity and availability). Scan down the list and find ones with a rating of at least 3.75. You can sort on avg score, but you'll have to skip all the ones with only a few reviews as those are likely one-off, tap-only, and/or non-distributed - so you probably can't get them. https://www.beeradvocate.com/beer/style/9/?sort=revsD As not all fruited beers fall into that style, it would be helpful if you would do two things. Firstly, modify your account profile to show us which country or state you are in, so that folks can consider availability in your area when making recommendations. Secondly, let us know more about the fruits you like, how fruity you want, and the other beers you've had that you like - fruity or not. Fruity beers still have a base style - and it helps to know this too. For instance, a lot of fruity beers are sours - but if you don't like sours then no point in us suggesting them. As for good fruit beer examples, I like Lindemans Framboise which is a Belgian beer with raspberries. It is a Lambic-Fruit style, is slightly tart, a bit sweet, is only 2.5% ABV, and is packaged in an extremely thick/heavy corked and capped bottle. It is really excellent. If you live in a major US metro area, you may find it on tap. Ommegang Rosetta is good too, as is Founders Rübæus.
You might also want to look for products labeled "Shandy". Any other "Cool" examples? No. Seems to me, if you want to drink this sort of beverage, it's more advantageous to make them yourself (control the ratio, pick your own flavor and know the flavoring ingredients, lower abv, able to consume the beer and mixer "straight" if desired, etc.)
If there is a "cool" example, I would have to say it's what I would call the Brass Monkey, which is a 50/50 blend of malt liquor and orange juice. That funky monkey.
OP - have you seen this page showing beer places in Mongolia? https://www.beeradvocate.com/place/directory/0/MN/