I have created and deployed a custom master page using visual studio'. Deployed and i can see the master page under _catalog/masterpage
folder in sharepoint designer under the root site collection. But in the sub-site it is not visible under the _catalog/masterpage
.
Any suggestions?
You don't need it in subsites. Browse to Site Settings page of the subsite and click on the "Master Page" under "Look and feel" section. Select your masterpage(it will already be there)