Can I apply for a India eVisa if I have less than 6 months on my current one?

No, you cannot apply for an India eVisa while you have an active India eVisa. India's immigration system allows only one active eVisa per passport at any time. You also cannot cancel a current eVisa to apply for another one.

You can only apply for a new eVisa after your current eVisa expires. If you need to travel for a different purpose than your current eVisa allows before it expires, you will need to apply for a regular (paper/sticker) business visa.