The monomers used for the preparation of nylon-2-nylon-6 is are

Nylon-2-nylon-6 is an alternating polyamide of glycine ( containing two carbon atoms) and 6-aminocaproic acid ( containing six carbon atoms). 

$$\begin{gathered} n{\mathrm{H}}_2\mathrm{N}-{\mathrm{CH}}_2-\mathrm{COOH}+n{\mathrm{H}}_2\mathrm{N}-{\left({\mathrm{CH}}_2\right)}_5-\mathrm{COOH} \\ \mathrm{Glycine} \downarrow 6-\mathrm{aminocaproic} \mathrm{acid} \\ \left[\begin{array}{cc}-\mathrm{C}-{\mathrm{CH}}_2-\mathrm{NH}-& \mathrm{C}-{\left({\mathrm{CH}}_2\right)}_5-\mathrm{NH}\\ & \parallel \\ \mathrm{O}& \mathrm{O}\end{array}\right] +(n-1){\mathrm{H}}_2\mathrm{O} \\ \mathrm{Nylon} - 2 - \mathrm{nylon} - 6 \end{gathered}$$