From the above table, we can see that,
In $\text{Bombay}$, $CO$ & $MT$ has increased their market shares
In $\text{Calcutta}$, $BN$ & $MT$ has increased their market shares.
In $\text{Delhi}$, None of the products has increased their market shares.
In $\text{Madras}$, $HD$ has increased it's market shares.
So, according to the question, $\color{green}{\text{in}}$ $\color{red}{Delhi}$$\color{green}{\text{ the minimum number of products increased their market shares}}$ $\color{green}{ \text{in 1993-94}}$ .