People here saying that prelims can be conducted without declaring the result. Its not a valid argument as you are not factoring in the count of attempts.
It is highly illogical to force candidates to take prelims and have their attempt exhausted before finishing the prior calendar exam. Such thing happens in State PCS but there you have large no of attempt so it doenst matter but here each attempt is matter of death and life.
So whether they postpone or not, they have to conclude the prior year process, declare result and then go for prelims.