Jiocinema SDE2 Offer Letter

Hi guys, YOE - 3 ( backend media tech profile) So lately I’ve interviewed for Jiocinema SDE II role. I cleared all their rounds. After informing that ive been selected after 3-5 days of final round, they rolled an offer letter after a week which had a basic welcome page and a salary annexure It was just a simple word doc ( not even a pdf ) with the company masterhead ( it didn’t had date of joining, workplace , work timings, leave information & probation details ) After a round of negotiation, Hr informed in zoom call that it is a offer of intent and not offer letter, which will be provided after you fill your details in our portal. After filling the form on their portal, now the hr is saying that the earlier provided offer was only the offer letter and appointment letter will be provided on date of joining. Have you guys faced the same situation in Viacom18? Is it is just me? Moreover the company raised various red flags like hr not picking calls for a week or two, since after giving my final round the company took 1.5+ months to send their portal link . Moreover the hike % is below 30%.