Zerodha does not seem to track all companies. Search for a company you want to get data for, most likely output will be Sorry, we don't have insider trading data for this company yet.
I guess the data BSE is showing is independent of whether promoters bought on BSE or NSE. It gives consolidated data about their total buying from open market as reported by companies.
Is there any link which shows only acquisitions or allow me to filter result?
I know this link but it takes time to see each data there. Many times HDFC etc generate lots of rows there.