Dear student,

It is a tricky situation but the answer is simple. You passed the senior secondary exam in the year of 2016 so you should mention 2016 as the year of passing. You are saying that you secured more percentage in improvement, then you can mention the improved grades in the form. But at the time of interviews, you will have to carry both the marksheets . Only The one with the more percentage , shall be considered valid. Which is the improved one in your case.

And lastly, dont worry . This does not affect the admission criteria .As long as you have cracked the entrance exam and proved your caliber for the respective exam, you are pretty much good to go.