Applying 4 months before the intake is best option, 3 months proceesing time + 15-20 days for pass port stamp. Students who applied in nov, dec for may intake got stuck. Whereas, who applied in jan, feb got early results. IRCC prime focus is nearest intake. When intake time has passed then they process latest applications for next intake. This is not the process always followed but general trend. Sometimes applying too early, slows the process. Hold applications consumes a lot of time.