Is my brokerage account safe? What happens if Groww discontinues business?

Your assets and account are held by Apex Clearing and managed by ViewTrade Securities. In the event that Groww and ViewTrade Securities stop doing business, your holdings and account will be held safely with Apex. You might not be able to trade further till a broker is allocated, but your holdings will remain untouched. In the event that the custodian discontinues business, then you can avail the SIPC insurance of $500,000. 

In the US, investors’ holdings/assets are kept in seperate accounts and cannot be touched for business purposes or serve as collateral for companies/broker firms.