Question is how mobile are you and how much luggage you have to carry and if the connecting train is for example on the opposite track. I do not have any experience with Breclav but in Germany 3 minutes would not be possible or at least you would need a lot of luck (no delay of incoming train, perfect conditions to switch platform). IMHO I would say it is doable but with some risk but as Palal stated if you miss the connection just take the next train.

You probably can also check online on which track the first train arrives and on which track the next one departs to plan your exchange.