The Samsung Galaxy S6 Edge doesn't have a very good record trying to connect to non-Samsung wearable products. The Fitbit Charge HR has problems connecting with the Galaxy S6 Edge, and it looks like the TomTom Multi-Sport GPS Watch has similar problems.
In order for your Android phone to sync data with the Multi-Sport GPS Watch, you first need to download TomTom MySports App from Google Play.
Unfortunately, even though the Samsung S6 Edge will see the TomTom Multi-Sport Watch, it will invariably fail to connect.