Complex sentence: Two years later when his guru became "shonnasi" he came back to Pabna, but Mazumder was not satisfied and wanted to go to Lucknow to study music in Maurice Music School.
Split into simpler sentences: Two years later when his guru became (shonnasi) he came back to Pabna. But Mazumder was not satisfied and wanted to go to Lucknow to study music in Maurice Music School.