Which is better: An integrated five years course into DM neurology (NIMHANS) or completing my MD in general medicine and then specializing in DM neurology?

In my opinion, it’s best to complete an MD in medicine first rather than pursuing DM Neuro directly after MBBS. 

It is so because M.B.B.S. students receive minimal clinical exposure and therefore their interest in a particular field might not be genuine. They might later regret their choice. 

An integrated program is a 5-year program that requires a lot of commitment. So, if you go for a field you are not interested in, you will be wasting 5 years of your life. Even if you are sure of your interest in neurology, you may not actually like it when you start working. That being said, it's better that you do MD in medicine, have first-hand exposure to all the specialties, and then choose one for you. 

People often choose integrated courses so as to save one year of education. However, they fail to recognize the risks involved. 

Ultimately, unless you love neurology passionately and have enough exposure in the same, go for direct DM, else completing MD would be the safest bet.