Is it wrong/sinful/haram to fast on chandraat as I want to fast on chandraat because I don't want to miss the roza because sometimes people in india end up fasting for only 29 days because of misunderstandings relating to the moon.So I want to fast on chandraat can I or not?

Not sure, if you are suggesting that you will fast at 'night'. Anyway the fasting is prohibited on Eid Day (If you observed a fast and found out during the day that it is Eid, then you can break the fast). Wallaho Alam

Also I found following article for your better understanding wrt your question. Hope it helps

Fasting on doubtful days

Rule: The rule for fasting on the thirtieth of Shabaan when you are not sure whether it is the thirtieth of Shabaan or the first of Ramadan, then to fast with the sole intention of Nafl is allowed but to fast with the intention that if it is the first of Ramadan then it is my first Ramadan Roza and if it is not the first of Ramadan then it is a Nafl Roza then this is Makrooh-e-Tahrimi. However, if the thirtieth falls on a day where you always fast on that day then it is better to fast on that day, for example, if you fasted every Thursday and the thirtieth of Shabaan was on a Thursday then it is better to fast that day as a Nafl fast [Durr-e-Mukhtar, Radd-ul-Mohtar etc.].
Rule: On a day where there is uncertainty then you should wait until midday and if the news of seeing the moon arrives then fast that day and if no news arrive then eat and drink [Durr-e-Mukhtar].
Rule: To fast at the end of Shabaan for only one or two days is Makrooh and if you fast for three or more days then it is not Makrooh. Rule: To fast on the day of Eid is Makrooh-e-Tahrimi, also the same rule applies on fasting on Bakr-e-Eid and also on the eleventh, twelfth and thirteenth of Zil Hajj.