Without having the actual pattern in front of me, this is just a guess
Row2: ch1, sc1 in same, [inc] around, slst to close {12}
Rows 2 is basically just an increase row, you have 6 sc and you are going to put 2 sc in each one = 12 scRow3: ch1, sc1 in same, inc, inc, sc3, [inc] 3 times, sc3. slst to close {17}
Row 3 is ch 1, sc in 1st sc, 2 sc in next sc, 2 sc in next sc, one sc in next 3 sc, the inc in brackets means to do it 3 times so it would be 2 sc in next sc, 2 sc in next sc, 2 sc in next sc, sc in next 3 sc.This pattern may have been translated from another language and often times when this happens it loses a little bit of "normalcy" or this could be the way that the designer writes his/her patterns.
Hope this helps to clear some of it up. Happy crocheting.