In your horoscope matching there is Gana Dosha as the girl belongs to the Rakshasa Gana. There is 5-9 Nav Pancham Bhakoot dosha, and Antya Nadi dosha. The guna milan score is 13 out of 36. Bhakoot dosha gets cancelled but Nadi dosha does not get cancelled. Nadi dosha is related to progeny, You should do detailed Ghara milan to see if Progeny happiness is there in your horoscopes, if yes then you can do the marriage. If planets are supporting progeny then Low Guna milan count can be ignored.