Mukerjea, the former director of INX Media, appeared before Special CBI Judge Arun Bhardwaj where she accepted the pardon granted to her.
She accepted to record her statements truthfully and provide true and complete facts in connection with the case.
On July 4, the court allowed Mukherjee's application seeking to become an approver. The court also allowed the pardon application filed by her.
P. Chidambaram and Sivaganga MP Karti Chidambaram are facing trial in the case.
Last year, Mukerjea, after making a confessional statement, moved the CBI court to turn approver.
She is currently lodged in Mumbai's Byculla Jail in connection with the murder of her daughter Sheena Bohra.
CBI had contended in its submissions that it had come across crucial evidence regarding some conversations to which only Indrani was privy and hence she would help in consolidation of the case.
While CBI is investigating alleged irregularities in the Foreign Investment Promotion Board (FIPB) clearance granted to INX Media for receiving overseas funds to the tune of Rs 305 crore in 2007, when P. Chidambaram was the Finance Minister, the Enforcement Directorate is probing the money laundering angle.
P. Chidambaram has got interim protection from arrest while his son is out on regular bail.
( With inputs from IANS )