If i take admission into nsou(open university)in mathematics honours, will it be effective? i mean, the common syllabus of iit jam ma and syllabus of nsou? will

if I take admission into nsou(open University)in mathematics honours, will it be effective? I mean, the common syllabus of iit jam ma and syllabus of nsou? will it be effective than my regular course or not ? if yes then how and if no then how? will I able to be prepare well for iit jam ma after taking admission in nsou? please guide me and describe your opinion if I should take admission in nsou? I am now in bsc math hons second year and I know that I will loss a year in taking admission into nsou?