"We are disappointed that Rana was acquitted on the count of conspiracy to provide material support to the Mumbai terrorist attacks," Secretary, Internal Security in the Ministry of Home Affairs, U K Bansal, said in a statement.
Bansal said the government has taken note of the verdict pronounced by a US District Court in the Rana case following the finding by the jury that the Pakistani-Canadian was guilty on two of the three counts.
Rana has been found guilty on one count of `conspiracy to provide material support to the terrorism plot in Denmark` and the other of `providing material support to Lashkar-e-Taiba`.
The jury acquitted Rana of conspiracy to provide material support to the Mumbai terror attacks.
Bansal said the National Investigation Agency (NIA), which is probing the case against Headley, Rana and others, had decided to wait for proceedings to conclude in the US court before filing a charge sheet in an Indian court against the accused.
The NIA has also sought certain documents and evidence that were produced in the Chicago court and expects to receive them.
"After examining the verdict in the US court and after reviewing the documents and evidence that it expects to receive, NIA will take a decision on filing a charge sheet against Headley, Rana and others in an Indian court," he said.