Yes ,its possible to launch in stock exchanges; if Bitcoin considers as an asset/commodity/security by regulatory bodies then you can launch in NSE/BSE.
ETF definition: An ETF, or exchange traded fund, is a marketable security that tracks an index, a commodity, bonds, or a basket of assets like an index fund.
You are forgetting, in India authority still not consider bitcoin as commodity/asset or security. So it's not possible till govt. clear their stand about BTC.