Firstly, the plant doesn't look like any type of basil I am familiar with. More like a mint.

Secondly it appears to be rather pale and etiolated implying a lack of light. That could also account for the weak stems. Is it indoors? Can you possibly put it outside? If not can you give it more light?

Thank you for your comment. Actually it is Ocimum Sanctum (Holy Basil/ Tulsi). It is outdoors in a patio and used to get several hours of sunlight. However it has been getting very little sun light since September since it is North facing.

Yes, I just realized that it was being eaten by a green caterpillar. Subsequently the caterpillars spread to several other leaves. The worm appears at the bottom of the leaves and is camouflaged very well. It is difficult to find and remove manually. I just had to pluck half the leaves from this plant because of this infestation. I sprayed the plant with a soap and Neem oil solution a day ago but no effect so far.

Neem oil doesn't kill caterpillars. Bacillus thuringiensis does, and it's completely harmless to humans, soil and beneficial bacteria and insects.

Thanks. This year I have tried Spinosad powder, Diatomaceous earth and liquid BT as well 2 days ago. I see the same type of larvae eating the leaves. Let's see what happens.