This is the 4198th most frequent Russian word.
татарстане
The word "татарстане" is the prepositional case of "Татарстан," meaning "in Tatarstan," a federal subject (republic) of Russia.
This sentence uses 'Татарстане' in the prepositional case to indicate location.
Я был в Татарстане прошлым летом.
I was in Tatarstan last summer.
Here, 'Татарстане' is in the prepositional case, describing a feature of the location.
В Татарстане - красивая природа.
Tatarstan has beautiful nature.
This example uses 'Татарстане' in the prepositional case indicating the topic of discussion.