Land

I have a residential plot with widdth 5.85 mtr and length as 12 mtr in my registry but on actual my plot length is 11.25 mtr and widdth is 6.35 mtr , i constructed upto 5 feet height with map , now my neighbor is claiming that his widdth of about 4 inchs is encroached by me but his length is 11 mtr in registry and in actual he has 11.25 mtr but his widdth is less on actual then on registry but while calculating his length and widdth it comes as 3 yards more then on registry , now plz tell me what should I do now as he akready having more land then on regusrty ?