missed out few episodes

I missed out on a few k street episodes, can someone fill me up on the following plz, i saw till the part where simran, vansh and his sis have dinner in k-family's mansion, where simran sees a 'fake' smiriti and finds out her mum's dead, the next episode i see meesha in the mental hospital !!

a)what really happened to meesha(dweeb/smriti's mum)?

b)why did drone's parents leave the family ?

c) how did bikram re-enter the family?

d)meesha said to be dead at the family dinner, why did everyone play along( rest of the family)

e)Who is the fake smriti living in the house, does anyone in the family know?? i mean durin the accident, everyone thought she was dead rite ?