Thanks guys for all the valuable feedback. Today, I purchased Flame6 for 4k. It got activated within few hours.
Now I am able to connect to a wifi hotspot. But my usb tethering is not working with the router. I didn't wanted to flash ddwrt or any other firmware. One asus old RTN 13u was lying around, so tried that.. I wasn't able to configure that correctly.
Please someone share the setting of usb modem in router.
Many thanks