When i record a guitar part of my own and i want to replace the part that 'not exactly to the beat i can't do it! i tried on the click trac button or the snap button it does not work. is there a way to do it?

Overdubbing selected audio to replace less than perfect recordings is very common and called "punch in/out." It can be done in BIAB, RB and any DAW.

Charlie

Quantizing is for MIDI. Ex; if you recorded a piano part or drum part played on a midi keyboard, and some notes were to far off the beat, you could 'quantize" the track or sections of the track to auto-majically move the midi notes to the nearest 1/4, 1/8th, 16th, 32nd beat.
On an audio track you can Snap To Grid in a similar fashion. But you will first need to find and mark or split at all the peaks. I'm not sure if RealBand or BIAB has these type of features. Different DAWs have various techniques for this.
The best way is as recommended by Charlie. Overdub, Punch In, or record several new tracks or Take Lanes then cut/copy/paste/merge the best parts to one or two keeper tracks.
Since my main instruments are vocal and guitar I tend to simply record the entire part several times until I like what I did and keep it. This reduces editing time. For me anyhow.

Another option (depending where you are in the project) is to use the Audio Chord Window to change the Tempo map of the song.
This would require regenerating all the audio tracks to match the new Tempo Map. The MIDI tracks would automatically adjust.

Sometimes it's quicker to adjust the rest of the song to match your playing than to get a 'perfect' take.

Then, after regenerating, the other tracks would play along with YOU instead of you trying to play along with them.. of course, this also depends on just how far off you got.
IOW
Would people notice ALL the instruments changing tempo more than you being off on a perfect tempo?

Thank you all! Other question: is there a way to monitoring while i'm recording my own track. I mean while i'm recording guitar or voice and listening to a backing trac that gimme the beat be able to listenig what i'm playing myself in a headphone at the same time. It while hlep me spécialy for guitare solo.

Yes. The simplest way is to put a microphone in front of the guitar or guitar amp. Connect the mic to your computers Line In or Mic In. You will be recording the guitar and will hear the guitar in the room while listening to the BIAB or RealBand tracks through the speakers connected to your computers Headphone Out or Line Out Jack. If using headphones tilt them off of one ear.

If you give us a list of the equipment you have for recording we could give you better direction.

That's the question I have. The gear makes a big difference as does the driver for the soundcard. The right one makes recording in sync a snap. A bad combination and your tracks are all over the place and totally out of sync.

With tracks that are out of sync but consistent, you can use a DAW and slide them into place. You can also use Melodyne to sync things up. The best bet is to use the proper sound card and record the tracks in sync to start with.