Currently, I am doing RNA bulk seg analysis for two pools the tolerant and sensitive, after performing RNA sequencing analysis which software or method of association should I use for identification of candidate loci of tolerant and sensitive genomic regions
The term you're looking for is differential expression. There's lots of tools out there, but generally Limma Voom, or DESeq2 are the packages of choice. In future, members of the community will be a lot more receptive if you've shown some effort in trying to answer the question yourself. There are lots of posts on biostars surrounding the topic of differential expression, such as Q: What is Differential Expression