I have exit light on emergency circuits that have batteries in them. Are they required to have batteries since the inverter or generator will supply power to them in case of power loss? Please advise

What country and what State? Building Code isn't universally standard globally.

If you are in the US, most likely NFPA 101 applies. If you read the Emergency lighting requirements it allows battery OR alternate power supply. However, NFPA is minimum standard. A local body can require battery in addition to alternate power. World Trade Center found that damage to backup generators caused issues with egress. In addition, there are other requirements when using alternative power supplies. NFPA 101 can be read on line.

My advice would be to consult with your local building code authority on this matter. A battery backup makes sense from a safety perspective, and may well be the local/state law.

In Florida, 1 1/2 Hours required after outage.
I was asked to run emergency lighting for a seven story condo. All the walkways zig zagged, Aluminum fixtures Oxidized, Would have had to remove all Lights, Broken screws, retap, a nightmare to get the extra wire through to each existing walkway light the come off each with conduit . Would have looked Like CRAP. I asked the Fire Marshall if I could be allowed to Provide Back up power to the Walkway lighting, he looked into it, said yes. They have Fluorescent, not sure if Led Bulbs were available then, was a few years ago.
I measured the Current Draw, and would Require an Inverter, and 2 Battery Banks.
I always wondered what surrounding places thought when every one would lose power but them. Last I saw It Had Rusted Out and not maintained, They had Friends and Families Electricians take over, Nice people, don't realize the Importance. Future Lawsuit?
It's a Money thing.

What does the building code say?
Let's assume you are in the USA, then the National Electrical Code will detail legal choices for the sources of power that can be used for exit sign and emergency lighting. (See NEC Article 700.12)

If a generator is the only power supply to these devices the generator will be required to listed as a Level 1, Type 10, emergency generator. (See NFPA 110)
If a generator is listed as standby, it can be used but then backup batteries will also be required.

So to completely answer your question we need to know, 1) "Where are you?" and 2) "is the generator a standby or emergency?"