I have customized masterpage from seattle.master, then using visual studio I have deployed it and applied it to the root site through feature activation. However I am not seeing my newly customized masterpage on MasterPage gallery and is not listed on ChangeSiteMasterPage.aspx page on the dropdown.
Update:
Elements.xml:
<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="schemas.microsoft.com/sharepoint">
<Module Name="NewMasterPages" Url="_catalogs/masterpage" Path="NewMasterPages">
<File Url="custom.master" Type="GhostableInLibrary" />
<File Url="custom.preview" Type="GhostableInLibrary"/>
</Module>
</Elements>
Any suggestion?