My understanding would consider the double bonded carbon at position 2, to take precedence over the carbon in position 6 with a methyl substituent. I say this because I view this carbon as being attached to the carbon in the 1 position, which breaks the tie between it and the carbon in the 7 position. Carbons 1 has a double bond (counting as 2 C for this purpose) and is also bound to another carbon, while carbon 7 is bound directly to only a single other carbon. As a result I would assign the carbon with the double bond a higher priority (2nd) when determine the priority groups stemming from the chiral center at the carbon in position 4.