In case you need 3 min time frame in MT4 platform, you have to write a script for the same using MQL. I have script in hand for 10 min chart. So, by all probabilities, it is possible to get a 3 min chart through a script. You can request the same in this forum from programmers or place an order for the same in freelance web sites for programmers to develop the script specifically for you. It is not available in-built in MT4.