If you want to convert your OST data to PST,I suggest that you read the suggested blog that contains free manual methods. In this blog, four manual methods are described, you can try depending on your needs. The author described the methods in a simple way and told about all the features and limitations of these methods.
To use the methods, you can visit: https://www.datarepairtools.com/blog/free-methods-to-convert-ost-to-pst-file/
If you want to convert your OST data to PST,I suggest that you read the suggested blog that contains free manual methods. In this blog, four manual methods are described, you can try depending on your needs. The author described the methods in a simple way and told about all the features and limitations of these methods. To use the methods, you can visit: https://www.datarepairtools.com/blog/free-methods-to-convert-ost-to-pst-file/