Since it is summer due to sweat I got dandruf
I used some shampoos but no use and moreover some are toxic so I'm panic to use it for further applying

Can anyone suggest me good treatment for dandruf that can be applicable

You can try a PH balanced shampoo or Baby Shampoo. Also change your diet and add omega or flax.

Some times even ph balanced shampoos causing hair falls

If Ph shampoo doesn't work then diet is the answer. It can be a yeast/fungal problem.
It could be a zinc deficiency.
Try the omega or flax and some zinc.
Don't drink caffeine

Dandruff Home Remedies, Dandruff Causes and Treatment (http://www.home-remedies-for-you.com/remedy/Dandruff.html)

Cool... wil try to hit... is that will be reson of sweat in hairs since it is hot summer

Best thing I have ever bought was a coal tar shampoo...
It's a really dark brown shampoo and it doesn't smell the best but it gets rid of dandruff in a snap!

Cool... I will try out is that be available in india?