The PS3 needs to continually outsell the 360 by a decent margin for the next 6 months to have a chance of doing this.
The PS3 has sold about 3m in Europe compared to the 360's 4.5m or so. In it has managed to sell 3m in 9 months, which is amazing considering it has taken the 360 2 years to get 4.5m.
The PS3 is also 1m clear ahead of the 360 in Japan and this margin will continue to rise over the coming weeks/months.
The PS3 also needs to close the gap on the 360 in NA. It needs to keep up with the 360 in sales to have a chance.
In short, yes the PS3 can outsell the 360 with just Europe and Japan, but it will take a bit of time.
Prediction (June 12th 2017)
Permanent pricedrop for both PS4 Slim and PS4 Pro in October.
PS4 Slim $249 (October 2017)
PS4 Pro $349 (October 2017)
