I am looking out for older version of Riak(1.1.2) for MAC;I searched it on google but could not find it.
Any help will be great.
Regards.
From the docs section of the website, there is a Download Riak area.
http://docs.basho.com/riak/latest/downloads/
You can change the version you're interested in reading about and downloading by clicking the version number shown at the top left of any docs page.
Riak 1.1.2 isn't listed, but 1.1.4 is.