Will not acceptable

My father, retired central govt employee, died last December followed by 5 legal heirs. 1. Son from first (dead) wife 2. Second wife 3. Daughter from second wife 4. Daughter from second wife 5. Son from second wife His fist wife died in 1967, and he re married in 1976. My father constructed two storey bunglow during his life. The bunglow construction started in 1989 and completed in 1991. In a registered will, my father left ground floor to his son from second wife and top floor to the son from his first wife. He did not left any share to his second wife and daughters. His second wife was central govt employee (now retired) and helped him financially at the time of construction. But unfortunately, there was no written evidences maintained. Bank also not able to provide any statement for that period. Even after spending almost 40 years of her life, father did not left anything for his wife. Also, in the will, father mentioned that he spend money for his daughters education, marriage and helped them financially many a times, which is completely false. He didn't spend much for them as his second wife was earning. In this matter, can the non-benefited legal heirs (second wife and daughters) challenge the will?