I'm trying to implement interrupt from RB pins. But it doesn't work
You've got TRISB=1; but it needs to be set to 1 for each each input bit. If you are using all the RB pins as inputs, TRISB = 0b11111111; if your compiler supports the 0b for binary, or 0xFF for hexadecimal which is always supported.

You've also got IOCB=1111110; which you presumably mean to be in a binary number format, IOCB bits need to be 1 for every RB pin that you want to enable interrupt on change. Should be IOCB = 0b11111111 if you want all RB pins as interrupt on change inputs.

Numbers without a leading zero are taken as decimal unless you have a prefix such as 0b or 0x. Beware that a leading zero on a constant means it is octal (base 8).