Given your requirement as described:
var output = Regex.Split(input, "(?<!or.*),");
However, given your sample output it seems you want to split on ‘or’ as well:
var output = Regex.Split(input,
"((?<!or.*),)|(or)",
RegexOptions.ExplicitCapture);
4
solved C# Regex to split string by commas that are only before “or” [closed]