How To Exclude Duplicate Entries With Multiple Condition

My data set has a number of duplicate entries. But I would like to sort them out based on some conditions. Say for example my C2 code appears three time in the dataset. I would like to sort this multiple code using the time and i column.

Say for example, 871514 code appears three times in this dataset, and if this code appear within three years - time with a different (i column text e.g. public and private), I would like to exclude these three duplicate entries from my dataset. If this code appears within next three years from the date, but have same I column text (e.g.public versus public), I will keep them.

So each code will be considered based on three years of time and type of text in I column. If the code appears again later after three years, I will keep them.

So the codes need to be checked within three years time with i column text.

My dataset identifies the difference of dates between last entry and next entry.