Don't know of any problem with using stranded copper cable used on 4-20 maA analog signal. The recommended cable for 4-20 ma signal is twisted shielded pair wire with a drain wire. The shield is needed to eliminate noise and the drain is usually grounded at one end to drain the noise.
> For the Analog signal 4-20ma dc transmission normally used cables are 2X1.5smm cu twisted shielded pair wire armoured.
Armoured jacket is just a physical protection to the cable no electrical benefits. The cable jacket has to meet the environment or the space it is run in. If it is run in a plenum (air condition flow space), the a plenum type jacket is required by the governing code. If it is in the marine world, there is marine jacketed cable or type P cable to use. Armored jacket is just the additional jacket to protect the cable from being harmed.
>For 4-20mA analog signal can we use twisted pair, stranded
>bare copper cable? Kindly advise.
I assume you mean insulated twisted cable. It's not normal practice, as others have said you should use a shielded cable.
Tray cables with a shield are not too expensive, there's no need for a steel jacket.
For underground I have often used buried telephone cable, it's very economical, twisted but not shielded, the ground does that. I have seen 4-20mA signals run to a dam site via overhead telephone lines but that was pretty noisy with lightning around.