If you are planning to stay longer than 90 days, you need to apply for a visitor's permit. An application for a visitor's permit is always sent to the Migration Agency in Sweden, where the decision is made.
See the following link for required documents. https://www.migrationsverket.se/English/Private-individuals/Visiting-Sweden/Visiting-relatives-and-friends/Longer-than-90-days.html
You need to book online appointment for Consulate General in Istanbul to submit your application.
A national visa (D-visa) is only issued in exceptional cases. According to the law special circumstances must apply in your case. Note that a family visit is not considered special circumstances, neither that the processing time for a visitor's permit might be longer. The fact that you have previously been granted a D-visa does not automatically mean that you can get a new one.