Complex sentence: In those days the medium of study, till class V was totally in Gujarati and from VI onwards in English and second language was Gujarati and was then affiliated to WB Board and students had to appear for Madhyamik examinations for passing out.
Split into simpler sentences: In those days the medium of study, till class V was totally in Gujarati and from VI onwards in English and second language was Gujarati. The school was then affiliated to WB Board and students had to appear for Madhyamik examinations for passing out.