The property that was bought on your step grandmother's name by your grandfather shall be her own property.

If she is reported to have died then it may devolve on her own legal heirs consisting her own children and not including the children of the first wife.

If she has executed a Will on the said property and has died  then the beneficiaries of the Will shall acquire the properties left behind by her. 

In my opinion, even if there was no Will, if the property title document was on your step grandmother's name then her own legal heirs are entitled to inherit the property left behind by her.

Therefore before deciding to file any law suit claiming any share in the property, you may better discuss with a local advocate by producing all the relevant papers before him/her and decide further course of legal action on this.

You have to file suit for partition to claim share in property s it was bought in grand mother name for benefit of joint family 

refuse to vacate premises 

let them file suit for eviction 

You can file a suit for partition of property by metes and bound.

as per law as a grand child you are entitled to equal share in the property.. 

you can challenge said will in court of law. 

Yes, you have equal share with step siblings.

If will is forged than have to prove it. Without will, all child have 1/3rd share each.

No you are not eligible to claim any share from the property in name of step grand mother.

See if they file suit you can contest same and can drag the issue for long though result in same is uncertain.

If the said marriage is before 1955 and you are a hindu then you will definitely get share. Otherwise it will be difficult to get the legitimate share being second marriage illegal

1. You can file partition suit for getting share from property of step grandmother as their legal heirs.

2. If they produce the will in court then you can object on ground that will is forged and if will was present then why didn't they apply for execution of will. 

3. Till decision of suit you can apply for injunction orders for maintaining status quo.

1. IF you can documentarily prove (Bank Statements, Income Tax Returns, Purchase agreements, Step GM's source of income etc....) and by supporting witnesses, that GF acquired the property with his own earned money, THEN you can stake your claim in GF's property by filing Civil Suit of Claim, in the local Civil Court.

2. The above is irrespective of the fabricated Will or Dowry criteria or anything else. Dowry is received by the Male side (GF) and GM cannot receive any Dowry. There should be documentary evidence of source of money of Step GM, to buy property.

3. Under no circumstances, You CANNOT be legally asked /directed to move out of the GF's property without a Court Order (which will take another 20 years).

Dear sir

If you are in settled possession then produce all the documents and get stay order by filing suit for permanent injunction. Let them file a suit for declaration and recovery of possession on the basis of such will which may not be proved by them .