the primary outcome is the severity of oral mucositis will assess by Oral Mucositis Assessment Scale (OMAS) and secondary outcomes are pain will assess Numerical rating scale (NRS), Oral Assessment Guide (OAG), and Patient-Reported Oral Mucositis( PROMS scale) All outcomes will be recorded at baseline, and 8, 15 days
After signing the informed consent, the participant will be allocated to either intervention or control group, then each participant will use either 0.15% benzydamine (Comparator) or 4% tulsi (Intervention) four times a day and also once half an hour before each radiotherapy session.