Got RT in 1 subject and I have overall I've passed because i have 6 subjects can I give next year improvement in all 5 subject including that RT subject

Yes, you can appear for improvement in all 5 subjects next year, including the one in which you got RT. Since you have passed overall due to having 6 subjects, you are still considered eligible. Improvement exams are meant for candidates who wish to better their marks, so you can apply for all subjects together.