@Dayananthan
So the only function at your disposal for this will be the TimeZoneOffset function. And, it will sort of be a partial solution.
I would consider as a first step convert your current time to UTC -
DateAdd(Now(), TimeZoneOffset(), Minutes)
Then apply an offset to that with DateAdd for your ET.
DateAdd(DateAdd( Now(), TimeZoneOffset(), Minutes ), -4, Hours)
This will adjust the UTC by the ET (-4) hours.
Now...you can see, this is the partial solution part as it will not account for DST.
You might also want to browse this thread recently posted dealing with TimeZone conversions and how to get accurate results. Perhaps that will give you some more detail based on your scenario.