hi,

jee main exams held two times a year, a candidate are eligible to participate in both of the sessions i.e january and april, now candidates who has only attempted one session, january or april are also eligible to get a common rank and category score. candidates who have participated the two sessions exam, best performance  among the two sessions would be considered. so there is no preference for either of  january or april sessions, score and rank would be calculated as per the performance of candidates for the particular sessions.

hope you may understand.