What international rugby competitions are in the six nations window?

Stumpy: What international rugby competitions are in the six nations window?
Apart from the 6 nations, are there any minor international rugby competitions (E.G- Asian 5 nations?) on at this time, and can they use the irb 6 nations window to get professional players released?

Answers and Views:

Answer by Bill P
No. The top 5 five in the Asian 5 Nations starts 23.4.11.