For those traveling to Schengen countries from India in 2019, with Amsterdam as the first stop, my advice is to take a prepaid sim. I took a 3GB data plan with a 30-day validity from Lebara that came for within 15 Euros (less than 1200Rs in todays forex rate) and I used it for a lot of Whatsapp. Link: https://mobile.lebara.com/nl/en/unlimited/c/prepaid-internationaal-bellen-unlimited
You can use a Lebara App to check on data usage
There maybe other options but I didn't bother exploring as the friend who I was traveling with took the same plan a day before I did as the plan came with a liberal Lebara - Lebara plan 500 free mins + 500 free SMS).
About whether 3GB is sufficient: I'd say yes
After 14 days of travel across 3 schengen countries (Netherlands, France, Italy) , my friend was left with 0.5 GB and I was left with 2.6GB - I used offline google maps, Uber, basic google and Whatsapp, while my friend was far more liberal in his usage.
PS: Don't forget to disable or take out your indian SIM ASAP, else pay up like I did on international roaming charges.
If you plan to use the indian SIM< bear in mind that just 2 days of using Whatsapp on my generous Vodafone RED postpaid connection plan, cost me close to Rs 5000. (~65 EUR). I am just planning to remove my SIM next time, lesson learnt.