1. If a grammar is LL(1), then it has to be LALR(1).Is it correct??.
NO,It will be LR(1) for sure but we cant say about LALR(1).
2. Is there anything called as LL(0)??
No.LL(1) means one look ahead at a time,if it is 0,how will we identify the unique production
3. Do every DCFL has LL(1) grammar??
No.Every LL(1) has a DCFL corresponding to it,but Every DCFL need not to be LL(1),it goes one way.
4. Do every DCFL has LR(1) grammar??
Yes.A language is DCFL iff it is LR(1).
5. Can someone please specify, As we can say that every regular language is LL(1), what can we say for CFL,CSL,Recursive and RE??
I am not sure about this,but what i can say is that staring from CFL,CSL,REC,RE we might have ambuity in the lanuage as,so it should be false in general.