As per the extant policy, Foreign Direct Investment (FDI) is permitted in the defence sector under the automatic route up to a limit of 49 percent.

Option 1: 26 percent - This option is incorrect as the permitted FDI limit in the defence sector is higher than 26 percent.

Option 2: 74 percent - This option is incorrect as the permitted FDI limit in the defence sector is lower than 74 percent.

Option 3: 51 percent - This option is incorrect as the permitted FDI limit in the defence sector is lower than 51 percent.

Option 4: 49 percent - This is the correct answer. The policy allows foreign investors to have up to 49 percent ownership in defence sector companies without requiring prior government approval. Beyond this limit, government approval is required.

It is important to note that this information is subject to change as per government policies and regulations.