Why do the inhabitants of some nations refer to the country as Motherland, and some Fatherland? The answer is a little complicated, unsurprisingly.
The use of both terms became most common in works of propaganda during World War II. This is particularly evident in the cases of The Soviet Union and Germany. Many Soviet propaganda posters of the time feature the phrase za rodinu! (For the Motherland!). Rodina, the Russian word for homeland, is a feminine noun, and many related words with the stem rod are associated with motherhood, fertility and procreation, so it perhaps makes sense that Russians would conceive of Mother Russia.
On the other side of things, German wartime propaganda often referred to the Vaterland. Interestingly though, German also contains the words Mutterland (motherland) and Heimatland (native land), so it seems like the use of Vaterland was a deliberate choice to convey a sense of strength and power.
Things can get confusing with Romance languages, which use words with roots associated with fatherhood (la patrie in French, la patria in Italian and Spanish), yet are also feminine nouns, so they can be equally translated as motherland or fatherland.
The fact that it’s so complex, and many languages allow one to use fatherland or motherland, probably speaks to our complex relationships with our homelands (isn’t it just so much easier to use that word!). We think of as stereotypically maternal: as providing for us, and caring for us. And yet, particularly in times of war or when conflict threatens, we want to see them as stereotypically paternal: strong and willing to defend us and attack anyone who threatens us.
So whichever you choose to use is up to you, depending on how you feel about your homeland (definitely less complicated!) at a particular moment.