how can i became IAS officer after taking MEC group in intermediate ??

Hello,

There is no such restrictions of belonging to specific stream when it comes to UPSC, as its eligibility criteria states that candidates need to pass graduation in any discipline from a state university, there is not even specific aggregate required in this case, you can apply in the final year also, the age limit is 21 to 32 years for UR, relaxation in terms of age is provided to reserved categories, after choosing MEC group in intermediate you can go for any field graduate degree as per your preference, last year itself one of the topper secured IAS belonging to commerce stream, similarly there are medical, engineering, arts, science graduates to name a few signify the diversity, hence you should pursue graduation in subject of your interest, also if at this moment you are not completely sure of UPSC, it's good to have a back up plan also as this exam is highly competitive, got such extensive syllabus, it takes single minded focus, dedication and perseverance to qualify, once you get into college you can start off by going through syllabus in detailed manner as this will help you to know what to read and what to skip, making a habit of reading newspaper everyday especially editorial, national and international importance news, economy, government scheme etc, go through NCERT first and then move towards other standard books, keep the list minimal, go through previous year paper and mock tests on regular basis to evaluate your preparation level.