Question about Shares as Margin

Haven't traded in Futures before...so here's a perhaps naive query..

I allocate certain shares as margin and the limit on that = 50k
I want to buy a lot of futures which is worth 30k.

1. How much do I have to pay in cash initially and when? T, T+1?
2. I understand that MTM losses will be settled in cash, when is the cash required? T, T+1, T+2?

Thanks

Any takers?

NIL

Next day morning.