When $2$ tuning forks (fork 1 and fork 2) are sounded simultaneously, $4$ beats ${{\rm{s}}^{ - 1}}$ are heard. Now, some tape is attached on the prong of fork $2$. When the tuning forks are sounded again, $6$ beats ${{\rm{s}}^{ - 1}}$ are heard if the frequency of fork $1$ is $200\,\,Hz$, then what was the original frequency of fork $2$?