salaam and thank you for the above answer. can you please clear my doubt for the following?
Can an istekhara be taken for a groom or lady before their families meet? Someone said personal meet of families is needed prior to istekhara. Pls advise.

No it is not needed .
Allah has granted us intellect we must do according that if still one is unsure then consult friends and experts and seek advice from them and last stage is Istekhara if one is still in doubt things are not clear then you can go for Istekhara.
I hope that now it is clear.