Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_12283621_6 (serbian_league_east VARCHAR, serbian_league_belgrade VARCHAR)
### Question:
What team was promoted in the Serbian League East in the same season when Kolubara was promoted in the Serbian League Belgrade?
### Answer:
SELECT serbian_league_east FROM table_12283621_6 WHERE serbian_league_belgrade = "Kolubara"