Impact factor is the average citation an article in a journal received per year or the past n years (Maximum n is taken as 5)
NAAS (National Academy of Agricultural Sciences) score is based on this impact factor in addition to their own evaluation. NASS classified all journals into two categories. First category consists of journals which received impact factor from Thompson Reuters. Rest of the journals are assigned to category two. NAAS score of category one journals is estimated as 6 + Impact factor with an upper limit of 20. NAAS score of second category is assigned by the evaluation of the NASS board. It is highly impossible to evaluate the scientific content of all journals and assign a own score.
NAAS score is indirectly based on Impact factor and own evaluation. Therefore, Impact factor is more important than NAAS score. Further, no academic body in INDIA is corruption free. UGC approved journal list is an explicit example of worst corruption.