The GTX 1080 is coming later this month for $599 USD. The Pascal GPU will have a slightly higher TDP than the outgoing Maxwell GTX 980 with a claimed 70 percent increase in performance.
http://www.notebookcheck.net/Nvidia-announces-GTX-1070-and-1080-with-potential-for-notebooks.165196.0.html
I was thinking of buying Asus ROG GL552VW (GTX 960m), but since these graphic card announced, should I wait for price cut in notebooks in near future "so that I can buy an Alienware 15(GTX 980m) " or just go for Asus.
"When will it affect Indian market, since I am from India."
It will probably take at least two or three months for these launches to have an impact on the prices of current products.