Startup vs Small Product Company?

Hello

I’m an undergraduate fresher from tier-3 college.

I’ve two job offers in my hand, one is from a Startup and another is from a small product based company (I got both the offers by directly applying on company portals). The work and technology stack at both the companies is similar.

I’m confused between either of them.

The work environment at startup is expected to be hectic (as mentioned by hr during interviews) along with 6 working days and frequent overtimes. Whereas at product company, it is 5 working days and limited to office hours (45 hrs a week) (verified from one of the senior who works at the same company).

The package been offered at both the places is also similar (5lpa in startup and 4.2 lpa in the other).

Apart from job, I’m aiming to improve my cp skills(and want to practise everyday) and prepare for top-notch companies.

I would like to know which kind of work environment should I prefer?

Thank you!