How much cash can I carry while travelling from India to Poland?
There is really no limit set on the amount of cash you can carry into the country.
The only difference is whether or not you need to declare it when you cross the border which according to EU Regulation 1809/2005 is 10000 Euro.
The only thing is that when you carry amounts of that size or larger Customs and various other agencies start to get curious on where this money came from.
Additional Info as per @Annoyed's comment
From the site of the Customs office at Mumbai Airport
Export of foreign exchange/currency notes:
Indian residents going abroad are allowed to take with them foreign currency upto any amount so long as the same has been purchased from an authorized foreign exchange dealer as per norms.
Any person resident out of India is allowed to take out of India unspent foreign currency not exceeding the amount brought by him on his arrival in India provided that in the case of foreign currency notes exceeding US$ 5,000/- or its equivalent or foreign exchange in the form of currency notes, bank notes or traveller’s cheques exceeding US$ 10,000/- or its equivalent, the same was declared to the Customs authorities in Currency Declaration Form (CDF) at the time of his arrival in India.
So long story short. Still no limitation as long as the source can be proven legitimate.
+1 those are the rules for import in the EU but there are also limits regarding export from India.
Of course there are also potential stop overs but I think I'll skip those for now. :)