Both would confirm...you can choose what to keep and what not to keep...also you can cancel the sleeper ticket tomorrow morning because the final chart would prepare later in day tomorrow for burhanpur...so yes even if all gets confirm by tonight you can be safe and can keep both tickets non cancelled till tomorrow morning
please note if all the tickets confirm(tonight itself) and you cancel the sleeper ticket tomorrow morning...money would be deducted but it wouldn't be the case that you wont get any money back at all