thing is
Every .torrent you Download is bound to your account by means of a passkey
this passkey identifies you to the tracker
Sample passkey
now when you signed up, the tracker has recorded your IP address associated with your account
if you enable your friend to use the tracker by supplying him the .torrent the tracker staff may suspect it as account sharing/trading
now here's what i would do
i would tell the tracker staff that i live away from home
i have a small server at the basement of my home running 24x7
and i have set up a remote web interface to access my server (or remote-uTorrent to be specific) and send the torrent files via net
so now, you have a credible excuse to be using 2 different connections
the tracker staff will most likely hear you and attach a note to your account allowing two different IP address/range(depending on static/dynamic IP) to access the account
case closed
BTW if you have invites to that specific tracker, you can invite the friend of yours to avoid all this trouble
@VishalK
about the scene ban , what scene ban?
the scene isn't even organised
even the tracker ban won't be done, well not unless the mod/sysop prefers being a very unreasonable guy with limited or none brain functions