If you want to have a basket approach towards a sector, cannot invest in individual stocks, but want to invest in a sector, then investing in that sector’s index is one choice. And many indices don’t have index funds, only ETFs are available, so there is no other option but to invest in ETFs.
Nifty IT index is from NSE, there is another IT index from BSE, I don’t know if there is an ETF for this BSE IT index. And there are sectoral funds which invest in IT and other technology companies, you can check the funds if you want to. All these funds have either Nifty IT or BSE IT index as their benchmark.
So first you can check these funds and see if they have beaten their respective benchmarks over a period of time, each year, YTD etc and choose the funds, if you want to go that way. Else, go with ETFs.
If you want to go with ETFs, choose one with liquidity, NAV-price difference, tracking error, AUM, inception date etc.
Nifty IT index has lesser stocks than a fund that is based on this index or the BSE IT index, and I think more than 50% weight of the index is from the top 5 IT companies, in other words if these big companies rise index will rise, if they don’t perform, index will not. On the other hand, an IT fund has a wide range of stocks to choose from, including the IPOs I think. So this is one important aspect.
So collect some data, know about the available choice, have a plan as you want to invest for long term.