@Nio484
I know it's not a convenient situation for our players in Czech Republic, Poland and Hungary, since they cannot get a full Mass Effect 2 experience ☹️
With consoles (Xbox 360 and PS3), I can only assume that Microsoft and Sony didn't authorise DLCs to be released in their stores in those countries, because certain languages are not supported. In other words, they are not compatible with Czech, Polish and Hungarian versions of the base game, therefore they cannot be available for download.
Unfortunately, there is no physical version of Mass Effect 2, which would include code for all the DLCs. Extra content is sold only digitally.
I'm not sure if creating an American profile on your Xbox would solve this problem. I can only confirm that all the DLCs are indeed available in the US store, but they probably won't work if you have a Czech version of ME2 on your console. Xbox support would be your best source information on this.
I'm sorry that I don't have better news to share ☹️
/Ataashi