The problem I am faced with while playing a barre chord is that the finger i use to make the chord behind the finger that's barring has to be place very far from the fret so the sound it makes is always muttered.
Is there a way to avoid it ?
Although you are referring to barre chords (E Minor "shape", by the look of it), I think of this as being the classic "A-chord-problem".
Often, one of the first chords a guitarist will learn is A (finger 1, fret 2, string 4; finger 2, fret 2, string 3; finger 3, fret 2, string 2), and although this is quite a basic chord, and a simple shape, it is actually quite hard to play. Why? Because you have to squeeze all three fingers onto fret 2 on adjacent strings. So, it is really hard to get the first finger note to sound well, as it is further from the fret. You often have the same problem with the kind of barre chords you are playing here.
For your chord, you need to do two main things to make the third finger note sound as good as possible:
As I've got older, my fingers have got fatter - or the fingerboards have shrunk. So, with the 'A' shape in particular, at the nut end, I may use middle/ring/pinky, by 5 or 6 fet I've only put 2 fingers on strings 2,3 and 4, and by about the 9th fret, it's ring finger across 2,3 and 4. Yes, all 6 strings sound clear (I tend to barre bottom also), and it's a lot more comfortable.
It is hard to tell without seeing your whole hand and arm, but I would say that problem could be avoided by lifting the guitar neck as much as needed and repositioning your wrist. Many people tend to play with the wrist laid back and then the fingers seem to be not long enough. In particular folk and rock guitar players tend to play with the guitar neck lower than they should therefore limiting their reach and risking tendon injuries.
When playing chords that need wide stretches there are two main things that can help. First, most of the times finding the right position for your wrist and thumb (thumb might also be positioned too high or too close to your barring finger), and second stretching exercises.
One good stretching exercise I have been doing almost daily for many years is:
One trick to reduce stress on your barring finger that could also help to increase your reach, is to place your barring finger on the strings in a way that your articulations fall on top of a string. If you choose to use mostly the fleshy part of your finger you will need more pressure, which will lead you to place your thumb closer to the barring finger.
Hope this helps. DP