how to become lecturer in any university if we have done graduation from b.a economics honours.

First complete your post graduation and then appear for NET Examination, if you are clearing the same , you may join as lecturer, or after post graduation you may join PhD, after completion of PhD, you will be eligible for the lecturer job.

It would be better if you do MA and then either M.Phil or directly PHd. That would get you a good career in college education. And yes as stated rightly by yeseducatin you need to clear NET exam. That is compulsory now. This exam is held twice in a year and there is no age limit for it as of now

try for net exams/ @ B.ed

First of all, you have to complete your post graduation than give NET exam conducted by UGC than you will be able to be a lecturer.