Dear Deepak,
From people's experience, we have seen that YEA is not allowing to
change plans from Option2 to Option 1 or the other way around.
That would suggest to me, that partial payment is discouraged and they
would like you to follow your allotment letter's payment schedule.
So we all have 2 choices,
a) Original payment plan
OR
b) 100% payment plan.
HTH.
Arnab M