Hi ManDeep, You can buy ETF’s for both Sensex and Nifty50 on Zerodha.
Almost all big AMC have their ETF, but as an investor we need to look for the most liquid ETF trading with highest volume and the one with lowest management fee.
I personally have held ICICINIFTY and SBISENSEX as they both offer good liquidity.
Both of them have lower price also making it attractive for retail investor like us, so that we can even buy in small quantities.