Two blocks of mass $M$ and $m,$ are used to compress two different massless springs as shown. The left spring is compressed by $3cm,$ while the right spring is compressed by an unknown amount. The system is at rest in equilibrium, and all surfaces fixed and smooth. Which of the following statements are true ? 

 

Let F be the force exerted by mass m on mass M.

FBD of mass M  

$F=k_1{x}_1=2\times 3=6N$

FBD of mass m  

$k_2{x}_2=F=6N$ to the left 

 Hence the force exerted on block of mass $m$ be the right spring $\left(k_2{x}_2\right)$ is $6N$ to the left. From FBD, the normal reaction (F) between blocks is 6 N. As system is at rest, net force on block of mass m is zero.