@Tarun vyas the warning associated with the EX4600-EM-8F expansion module and use of Copper SFP transceivers (1000BASE-T) is no longer valid. Juniper has not yet updated documentation regarding this specific 1000Base-T/Copper Optic.
The prior situation was that the physical characterists of the Optic were such that physically you should not install these [now older] Optics in adjacent ports - either up/down or side my side. Now one 'could' try to do this and maybe succeed, put the added pressure could create problems - one would need to physically "force" the optics into the ports. The net result was that for this 1 specific 1GE optic, you were limited to 1/2 the available ports. The other ports could be used for any other 1GE optic. That is where this comes from:
If we use four port with copper SFP transceivers (1000BASE-T) Can we use remaining four port with fiber SFP transceivers (1000BASE-X).
BTW this statement below is inaccurate. The real restriction is top port of port column #1, then bottom of port column #2, then top column of port column #3, etc. Could not be top and bottom of same port column, nor side by side.
Copper SFP transceivers (1000BASE-T) are restricted to the top four ports or the bottom four ports
## Is it strictly restrict to use top four port or bottom four port. or we can use any for port like three any top four port and one any bottom port.
Anyway, this is all ancient history now. There is a new version for this optic (been shipping now for last 3-4 months) that is 'slimmer'. This slimmer version does not have the physical restriction of the older (not so slim) Optic.
With the newer [now shipping] Optic, you can use 1000Base-T/Copper 1GE optic in all ports, no restrictions. If someone has the older 'larger' Optic, they can RMA for the new slimmer version.
I think I reply with something similar to another thread asking about these Optics. Hopefully soon Juniper will update all the documentation regarding this situation.