I’ll be sharing with you my opinion on both.

As a 6-year MCh candidate, you’ll rotate through 10 months of general surgery. However, general surgery skills aren’t of much use in Neurosurgery, except the very basic knot-tying and suturing skills. You can also acquire those from dedicated lab practice. The other techniques followed in Neurosurgery are very different from those followed in general surgery. 

Neurosurgeons generally use access surgeons (thoracic surgeons or urologists) to perform unconventional approaches to the spine. It is much safer for the patient. Also, opting for a 6-year course after MBBS means one less entrance exam.

So it isn’t very beneficial for you to take up 3 years of MS general surgery. I would recommend you choose the direct 6 year Mh Neurosurgery course at AIIMS or NIMHANS instead.