i have seen several post but i am still not clear of wat to do.could you help me with link or step to step info on how to configure.

i have beetel 450tc1 and i am now using tata BB.i got two rj 45 .wat configuration i need to do exactly on router page to make wifi work.i flashed beetel 450 tc1 and updated to latest firm.i am not able to change the static ip it gives error when i save.(duplicate to lan ip network).If you guys can provide the SS for config that would be nice
What should i do .?

thank you.