@ kaarthiik:

If you have been able to grow them without issues, I've got nothing to say. :)

Depending on your location in India and the type of Vanda you have, you may be able (and it may be advantageous) to give your Vandas and Cattleyas some direct sun.

When adapted to brighter light gradually, both Vandas and Cattleyas grow faster with some direct sun. Here in SW Florida I have Cattleyas and Vandas that get several hours of direct morning and afternoon sun, and a few Vandas that even get sun at noon.

Always increase light gradually (give them at least 1-2 weeks in a new location) before moving again and watch for any signs of damage (sunburn). Move them back if you see damage. They will also need more water when growing in bright light.

India is such a large and varied country. Your conditions might be very similar to mine in S Florida, but they could also be quite different. Use your judgement based on altitude and latitude. If you see others growing similar hybrids, look at their conditions and light exposure. Just as India isd varied, the light and temperature tolerance is quite varied in Vandas and Catts.

Good luck and post some pics when they bloom.

to some extent it depends on what sort of grower you are as well.
I am a chronic over-waterer. I know this and therefore grow most of my plants in such a way that overwatering won't present a problem.
Vandas in pots must be very carefully watered and never overwatered. I grow mine bare-root and they do great with a daily soak and high nighttime humidity.