Annulment of marraige

I want to know the below things

1. In what earliest time the marrige can be annuled

If both parties agree for annulment, it can be done by six months to 9 months.  If it is mutual consent divorce (MCD) you have to wait one year from the date of marriage and further six to 7 months it will take to get divorce.

2. Am i liable to pay allimony to her if demanded ( she is employed ).

If she is employed and earning equally then generally "no", but payment of alimony depends upon other various factors.  If she is also interested to severe the relationship, she may not demand for the same. 

3  The marraige has not been registered except for the Gurudwara , do still need to annul the marraige / divorce legally .?

Yes.

4 Although no dowry was involved since it was a intercaste marraige , can they file a case of dowry on me and my family ? How should i protect my self from this .

If they file such case, the burden is on them to prove of giving dowry.  Then only the burden lies on you to disprove the factum of receipt of dowry.

5 .Do i need to give all the gold back to her as part of Stri dhan including the ones that were given to my family members . I dont mind giving back what she got from her end , but have issues in giving back what we gave .

As per the descripttion of stri dhan,  presentations which are  given atthe time of marriage to the bride (without any demand having been made in that behalf).  But you have a saving proviso - "provided that such presents are entered in a list mained in accordance with the rules made under this Act.

So, you have to return the gold she brought from her home.  If you are benevolent, you can give your gold also as it is presentation given to her.

6 Can i file pettion here in Mumbai , or i will have to file it in delhi since we got married there , will i get a verdict in one sitting , or i will have multiple sessions .

Better to file it in Delhi, even though Bombay has got jurisdiction as you both last lived together.  You can file only annulment case within one year of marriage.  For filing divorce petition, one year period from date of marriage is required.

7 what will be the Charges for appointing a lawyer on such an acount . Can one lawyer represent both .

Lawyers' fee depends upon the lawyer.  In annulment cases and contesting divorce cases different advocates are required.  Only in MCD cases, one lawyer will do.