According to reports, India has raised objections in regard with this matter at both political and official levels in China as well as to the Nuclear Suppliers Group (NSG) in last few months.
The report also said that the deal for two nuclear reactors is valued at $9.6 billions and will be located off Karachi.
Sources said that India has made it clear to China that any "deepening nuclear ties between Pakistan-China" can have serious implications for India.
The talks of China selling nuclear reactors to Pakistan first emerged last year, then India reportedly took up the issue to the NSG interlocutors.
India has raised objections at both political and official levels with China.
However, China, who is firm on selling nuclear reactors to Pak, has said in its response that the decision of giving nuclear reactors to Pakistan falls within the "Sino-Pak nuclear cooperation agreement".
Last month, the Minister of External Affairs, Salman Khurshid said in an interaction with the visiting delegation, which included journalists from the state-run Chinese media, "Nuclear relations between China and Pakistan "have a more lasting impact of question mark or a concern. Although you have a relationship with them, and we have no problem that you have a relationship with them, our concern in your relationship with Pakistan is only about the impact on nuclear non-proliferation. That is one concern that we have expressed to you."