Not very far, unless they make a series of conceptual breakthroughs beyond "this thing will shock you" that they frankly have no background to guess and start developing. This is going to be a strange novelty for a very, very long time. Luckily, they do have a written culture, and if the shock bottle makes it into the right books, it stands a chance of reemerging once the intellectual conditions are right and ideas about electricity start to circulate. A Leyden jar equivalent reaching Europe in the 1650s could really initiate some interesting developments.
In India proper, in 450, even basic chemicals for expanding their electrical experimentation further (like sulfuric acid, key to lead-acid batteries, believed to have been first intentionally created in the 900s near Baghdad by Islamic alchemists) simply don't exist or are completely unavailable.
The key to their version of the Leyden jar is silver foil, and they have no reason to work out that cheaper options like copper or lead foil could work instead, since they don't have a tradition of making such non-food-safe metals into thin foil. So these shock jars are going to be extremely expensive, which will limit how widespread they are and what kind of experiments people are willing to do with them.
They have no reason to connect this type of shock to lightning, and no access to animals like the electric eel which could make them realize this is a broader phenomenon. Compasses and magnets, both of which exist in India at this time period, are too rare and expensive for anyone to realize they react to a completely unrelated extremely rarre and expensive novelty. Without a very deep scientific base, there just isn't any easy way to start making electrical engineering developments combine and compound with each other.
To them, this will be, at best, an expensive toy- but it just might be an expensive toy that sticks in people's minds, and centuries down the road starts to inspire further experimentation when the chemistry and magnetism knowledge starts building to the point where it could be taken advantage of. Also, if any description of these things makes it into any kind of Hindu or Buddhist holy text, then when its rediscovered in the modern era it will absolutely become a talking point for devotees of that religion.