The bench directed the trio, who are currently out on bail, to surrender before the jail authorities by September 30.
Earlier in 2010, a fast track court in Rajkot had acquitted Jadeja in the case. However, of the 16 accused, it had found Samir Pathan, an alleged associate of Jadeja, guilty and sentenced him to life imprisonment.
Subsequently, Pathan as well as the state government approached the high court against the lower court's verdict.
While Pathan pleaded innocence, the government challenged the acquittal of 15 others in the case, including Jadeja.
The high court today reversed the lower court's order as it found Jadeja and two of his aides guilty in the case.
However, it acquitted Pathan as Ramji Makwana, a key eyewitness in the case, told the court that he saw Jadeja firing at Raiyani and the other two convicts accompanying the MLA at the time of the incident.
According to the case details, Raiyani was shot dead on February 8, 2004 when he, along with two of his friends, including Makwana, was travelling in a car.
Subsequently, an FIR was lodged against Jadeja and 15 others in connection with the killing of Raiyani.
In his testimony, Makwana had told the court that he saw the BJP MLA step out of his car and open fire from his weapon.
Makwana had escaped the attack unhurt.
According to Pathan's lawyer Aftab Ansari, Raiyani was killed over a land dispute as several parties were claiming ownership of a tract of land on the outskirts of Gondal, which resulted in the bloodshed.