Right on ancestral property of husband by second wife

Dear Sir/Madam,

Since your case is complicated case as such I require documents and same may be send to my email for detailed legal advise.

with regards,

Kishan Dutt Kalaskar

Dear Sir,

My sister got married with  Mr Suchit Prasad in 1988. The first wife had left him before 2 years and fled with another man. She left two kids i.e. one boy and one girl. My sister had no child. After 15 years, her step son had started beating and threatening her. He and her father both are selling land which is ancestral property of the father of Suchit Prasad. Total land in area is 18 decimal in which they sold 12 decimal and signed the documents by both. Now, her step son is planning to sell out all the property and debarred my sister from the house forcily. Now, my sister is second wife of Mr Suchit Prasad.

Question : Is my sister having right on left over property on her husband ancentral property?