Does anyone know how to setup the minimum fee in the electrum while sending the coins.
You can either change the slider to "static" and slide it all the way down to 1 sat/vbyte, or you can enter the advanced preview and manually enter the fee of 1 sat/vbyte.
If we set the very low fee, how long will it take for the coins to reach the destination.
Depends entirely on the state of the mempool and when the next blocks are found. It could be as fast as less than a minute, or it could take weeks. At present, 1 sat/vbyte would put you 25 MB from the tip, so it would likely be well in to the weekend at a minimum before you would be confirmed.