The root five Major bar chord is derived from the basic A Major chord and features a third finger bar across the 2nd, 3rd and 4th strings.
You may find it difficult to avoid touching the first string with the third finger whilst fingering the root five Major bar chord. However, it is common practice to mute the first string with the third finger as an alternative fingering for this chord.
You may also prefer to bar the first five strings only and mute the sixth string with the tip of the first finger. Now the key note will be the lowest note produced when the chord is strummed, helping to give a clearer, more accurate sound to the chord.