Not only the size of your Navy will need to be increased, the ability of the IN to do a blockade is history with this extension (as long as PN can maintain a good number of vessels and area denial systems). This extension will force India to place her AC and other offensive ships about few more hundreds miles out, so that would mean, 400-500 miles from the Karachi sea line so they are protected. Meaning, additional 800-1000 mile worth of flight before an offensive jet can reach to the port of Karachi, this limits fuel, weapons carrying capability and refueling options. The extension alone has a huge impact on limiting IN's abilities against Pakistan.