Immigration Minister Nathan Guy said he could not comment on the matter as it was before the courts.
"I would point out that these changes were first made public in early March, so there has been plenty of notice of the Government's intentions," Mr Guy said. "The Government has the sovereign right to make decisions around foreign nationals entering and staying in the country."
The parent category will re-open in July under a two-tier system where applications made by wealthier sponsors will be processed faster than those on lower income.
Mr Guy said the changes were to ensure that "new migrants and their families are self-sufficient, can settle well and are able to contribute to New Zealand".
The lawyer for the Supreme Sikh Council, Frank Deliu, said the new policies were "unfair" and is applying to the High Court in Auckland seeking interim orders against the "sudden policy changes".
The council claimed the changes were a breach of legitimate expectation and that the agency had failed to take into account relevant considerations, such as the right to a family.
"Soon after the announcement, hundreds of people being Indian, Chinese and Fijians approached the council with tears in their eyes, saying they have been unfairly treated by this policy," said spokesman Daljit Singh, a licensed immigration adviser. '
'They have spent a lot of money and are just waiting for the original certificates to arrive, we have plenty of cases where parents have completed their medicals and police clearance in their home countries."
Immigration adviser Maricel Weishede, director of NZ Immigration Help Service, also had several clients left in limbo. She would also be writing to the agency appealing for an extension for them.