The Belgian giants only snapped up Roofe last summer from Leeds United, paying €5.5m to take the striker to Lotto Park.
Anderlecht have now opted to cash in on Roofe and, according to Belgian daily Derniere Heure, are earning €5m from selling the striker to Rangers.
Bonuses could affect the final total of the fee, but the Belgian side are taking a loss on Roofe at present.
The striker was expected to do big things at Anderlecht, but saw injuries affect his time at the club and made just 13 appearances in the Belgian top flight.
He scored in big games against Gent and Standard Liege however and will now bid to hit the ground running at Rangers.
The Scottish Premiership season kicked off at the weekend, with Rangers getting off to a winning start with a 1-0 win at Aberdeen.
Rangers next face Bayer Leverkusen in the Europa League on Thursday evening, trailing 3-1 from the first leg.