How to remove HTML code from rss.xml
Easy way to do this in D7 is through the Display Format settings. Under the content type(s) of the nodes in your view, you want to add a custom display for RSS and then set the fields you want to alter to plain text.


Go to Structure -> Content Types, and select 'Manage Display' next to your content type.
On the bottom of the list of fields, expand 'Custom Display Settings' and check the box for RSS and save
Now, in the upper right-hand corner you should see that you have display format settings for Default, Teaser, and RSS - select RSS.
In the format settings for each of the fields, you want to select 'Plain Text' or whatever equivalent you like.