i want to know before buying the chromecast in india please inform me asap
Thanks in advance,
Here's Google's Router Known Issues & Workarounds.
It's also worth checking Google's Router Compatibility list, which is a bit more comprehensive.
At least one person needed to disable Parental Controls on their router. Access Control and Content Filtering do similar things so if you are having trouble, try toggling those options as well.
Also, there are some WiFi Bandwidth and Router considerations to consider as well. Sustainable WiFi bandwidth is critical for a smooth casting experience.