To help when you're searching, realize orchids in the genus Ascocentrum were moved by botanists into genus Vanda. Most botanists have accepted this transfer. You might find more information searching on Vanda ampullacea.
The key to your plant's survival is keeping it well hydrated until it grows new roots.
These shouldn't stay wet all day, but they do need water every day if mounted or bare-root. If your climate has high relative humidity that will help, because the plant will lose less water through transpiration.
The Vanda group of orchids can use large amounts of fertilizer. I agree you wouldn't want to risk damaging roots now with a high concentration of fertilizer. However, tiny Vanda plants hardly grow at all without nitrogen. I would use low amounts of fertilizer at least weekly. What fertilizers are available to you?
Ray, who responded above, sells a kelp product containing rooting hormones. My experience is it works well on small Vandas. It is called KelpMax, but only available in North America. The same product is sold in the EU as Kelpak. I don't know whether anything like that is available in India. There is a discussion of the product here:
Kelpmax in Netherlands