very low jiofiber internet connection

Just one day back I got the jiofiber connection. It is running well on my brother(windows 10) laptop(if i'm right we're getting 2.4 ghz wifi signal) but my laptop(windows7) is taking long time to connect and when connect the internet is too slow.

I believe it is my wifi network card that is incompatible but my laptop had no problem running BSNL broadband.

Will be thankful for any help.
First of all, do a speedtest on both laptops. If the speed is much lesser on your laptop then try connecting it with a LAN cable to the router. If the speed improves significantly then there might be an issue with the WiFi card or some other interference. You can test speed on quite easily as well as on Report back after you test and we can think of further steps.
Thanks. showed 150 kbps(1st attempt), 70 kbps(2nd attempt), 140 kbps(3rd attempt). With LAN cable its working perfectly fine. I have Ralink RT3290 802.11bgn wi-fi adapter. Its only my laptop which has the issues, other devices when connected working fine.
You can try booting from Linux, by this you can narrow down if it's your laptop's hardware or the software that is being the bottleneck.