In a series of tweets, Jaju said the 33-year-old "Quantico" star was extremely close to Merchant's mother and did not take her demise well.
"PC was very close to Aseem merchant's mother, her death in 2002 shattered her so much that she tried to jump off karan apt to commit suicide," Jaju wrote.
"I reached at nick of time and caught hold of her and tied her to a chair till grills were fixed in all the windows of the flat." The celebrity manager added he wanted to make a point "that suicidal tendency is in most of the girls of film industry."
"PC may look very strong now but she was also very vulnerable in struggling days, tried to commit suicide 2-3 times but I managed to stop her," he wrote.
Jaju said Priyanka and Aseem used to fight on daily basis and on one such night, the actress attempted suicide. "Daily PC and Aseem used to fight... She used to call me at 2 am in the night, crying... and I used to take her from Aseem's house, make her understand and drop her at her home.
"Once madam went to Vasai to attempt suicide after fighting with Aseem. I got her back. Girls don't act intelligently at the age of 18-19."
Priyanka, who is shooting in Los Angeles for her maiden Hollywood film "Baywatch", did not immediately respond to messages for her comments on Jaju's claims.
Jaju also spoke about TV actress Pratyusha Banerjee, who was found dead at her home on April 1 in a suspected case of suicide.