SCHEMA:
CREATE TABLE table_name_12 (became_acharya_on VARCHAR, name_of_acharya VARCHAR)
USER:
When did acharya shree koshalendraprasadji maharaj become acharya?

QUERY:
SELECT became_acharya_on FROM table_name_12 WHERE name_of_acharya = "acharya shree koshalendraprasadji maharaj"