We discussed this in chat, you need some way of decoding the extra data lines that are not being used by the decoders, to enable and disable the 4-16 decoders that you already have. This will need a 2 to 4 decoder that you can build yourself, as I showed you earlier, or you can try to get an IC that already has the decoder function built in. You can try looking into the 74139 as your 2-4 decoder, here is the data sheet for it: https://www.electro-tech-online.com/custompdfs/2011/12/74HC_HCT139_CNV.pdf
If you are looking for another way of doing what you want to, there isn't one unless you want to make the entire decoder from scratch.
how i can connect 4 dicoder to what or which gate or divice to make final (dicoder 6-64)?i khow what you mean.i can understand how i can use dicoder 2 to 4.t it would be 6 to 64?and could you explain how it work?i am just student.i havent more information.i need your help.
i am not stupic i cant explain my guestion right.and my english isnt good
.thanks alot
The 6 to 64 decoder will only have one output on at one time.
Are you going to step between all the 64 outputs in a sequence (1 -> 64)? If you are, then you could use cascaded 4017 ICs, the circuit will be much simpler.
The 2-4 decoder will always have an output active, this active output will drive the enable pin on the 4-16 decoders. Depending on the IC that you are using for the 4-16 decoder, the enable pin will be either active high or active low. When the enable pin is not active, the 4-16 decoder will not decode the signal at all, and all outputs will be at their inactive state regardless of the input.