I had started a company in the real estate space OP. We focused on brokers for a while and had thought about this . my father is also an agent and doing decent . he is also the president of AIBF Bhopal (a nation wide association of brokers )
short answer : do not do it .
Medium long : brokers basically rely on one big deal every month and 3-4 small deals. that's it. they anywat do not get a lot of leads or crack so many deals that they would require saas. Excel , word , pen , copy , phone are enough. the only thing they want is good leads.
If you are hell bent you can target builders instead. but there are already quite a few companies doing this. my suggestion is leave real estate . Its a very big market and has a lot of inefficiency but then unless the government brings in some rules and standardisation, it will always remain fragmented and chaotic .
R square is an old company already doing this for brokers. you can check them out.