So which is the best one? Dual degree or 4 year B.tech program?

generally BTech is preferred because for your degree you need to spend 5 years as well as it may happen that in future you lost interest in your department so if you choose dual degree then you are forced to do Mtech but BTech provide you more flexibility is Mtech is a more specialisation in that code so you are bound to to do that course only but BTech students are versatile their choose fields outside their branches and most of them do good in other fields as well