I'm playing pathfinder and I just recovered the ashes of burned papers. The Dm told me make whole wouldn't work because a big part of the paper went off in smoke and as such there isn't all the parts. Is there any divination spell that could help me recover some information ? I have access to a good amount of gold and a fairly large city so I could pay a spellcaster to cast it if it is too high-level. I have neither access to the vilain and the document is probably a little too much damaged to use linguistics on
Retrocognition may work for you:
This spell allows you to gain psychic impressions from past events that occurred in your current location. Retrocognition reveals psychic impressions from events that occurred over the course of the last hour throughout the first minute of the duration, followed by impressions from the next hour back the next minute you concentrate, and so on. If a psychically traumatic or turbulent event happened during that time period, you must succeed at a concentration check (DC = 20, 30, or 40, depending on the severity of the psychic disturbance) or lose concentration on the spell.
At caster level 13th and higher, you can choose to collect impressions from over the course of a longer interval of time than an hour, beginning at 1 week per minute of concentration (as listed on the table below). The amount of detail you receive diminishes, so this eventually makes it harder to distinguish impressions left by anything but the most major events.
If it's recent enough, you may be able to read the page as it was in the past, before it was burned, or see the person who wrote it so you can track them down. If you can see who wrote it, you may also be able to tell if they made a copy, so you can look for the copy and still get the information.
If the document is important enough, chances are there was a copy made, as you'd typically not destroy important information without having some kind of backup (ie. memorization, 2nd copy, etc.), so you're not necessarily out of luck yet, then you can use a Mind Probe to extract the document from their memories, or steal the copy from wherever it's stored (assuming one exists).
Psychic stuff is the way to go here
The easiest option is probably the 1st-level occultist spell Object Reading, which may give you a glimpse of the object in the past depending on how many pieces of information you can get (i.e. how high of an appraise check you or an NPC you hire can make).
There are higher-level options if that doesn't work.
The object seer ability available to a 7th level occultist can provide the information you are looking for at the cost of one focus point.
The Object Reading ability of a 2nd level occultist (not the spell) may also work, but if it works the 1st level spell should really also have worked.
The occultist's 8th-level Outside Contact ability lets one cast divination without the usual restriction to activity you intend to do within a week, and without any chance of failure or incorrect or incomplete knowledge. It costs ~10 gp per question, but the answers can be cryptic so if you want the whole message, you would probably want to spend 10 gp per word. If it's a map or diagram, using divination this way may be more problematic.
Regular non-psychic information abilities can also work, but you'd need to essentially play 20 questions with each word of a message or each component of a diagram or image, and that can take a long time. If you want to go this route, Spirit Planchettes are pretty much the cheapest option.
Some good answers here, but I can add that I believe most GMs would allow a Limited Wish or Wish spell to reconstruct document.
There is also Memory of Function which works like make whole, but it does not require all of the missing pieces in order to function. The missing pieces will remain missing, but the ashes should reconstruct to form a very fragile charred parchment and the ink may be legible.
At lower levels, Legend Lore or Vision might work provided the document qualifies as "important." From those spell descriptions, we can infer that the document would need to be renowned or historically significant, like the Magna Carta in our world, so your document likely does not qualify.