Not 100% accurate.
When the currency becomes unstable (depreciate faster than it used to be), then people look for other assets to protect their wealth.
People would buy
- Lands
- Gold or other commodities
- Speculated assets (Crypto) or
- Equities
So in a way, rupee depreciation could positively impact the equity market.
If you buy good businesses which are functioning properly with increasing net profits and growing asset values (not pump and dump junks) then you will insure your wealth against the depreciation in the long run.
However, if you are pumping all what you got in to the market, with the hope of short term gains, then you are gambling. That is not investing. So like in any gamble, you have a higher chance of losing.