The answer should have to be yes as long as the minimum requirements of grades/marks in diploma are fulfilled. I looked at the subjects in diploma in IT and found that it had the three major subjects–Physics, Chemistry and Mathematics of 200 marks, which are crucial for engineering, plus there are some subjects that are also taught in engineering! Actually I answered from TU, IOE’s perspective but the case is more or less the same for other universities such as KU, PU.
One of the brothers I know was from diploma in Civil engineering and he was studying Bachelor in Civil engineering at Pulchowk! But he said he needed to work a lot hard to secure a top rank.