Does the Progress DataDirect for JDBC for MongoDB driver support TIMESTAMP datatypes?
Why is the timestamp data returned by the driver different from the entered data?

The "timestamp" type in MongoDB is not related to the JDBC Date or Timestamp types - in fact, there is no JDBC type that corresponds to it. MongoDB does have an ordinary "date" type, which is like the JDBC timestamp. The MongoDB "timestamp" is something else entirely and ia mapped to VARCHAR.

The MongoDB documentation states:
Timestamps
BSON has a special timestamp type for internal MongoDB use and is not associated with the regular Date type. This internal timestamp type is a 64 bit value where:
- the most significant 32 bits are a time_t value (seconds since the Unix epoch)
- the least significant 32 bits are an incrementing ordinal for operations within a given second.

For example, a c_timestamp column has data entered as { "t": 1, "i": 2117514496 }. 
When using the JDBC MongoDB driver to connect to the database, the column is modeled as varchar(255) and a query on the c_timestamp column is returned as "0100000000B5367E". 

The result returned by the driver is a 64bit value that breaks down as follows:

The most significant digits: 00B5367E - This is a big endian hex value that equates to the 'i' portion in the $timestamp field. Using Programmer mode of the Windows calc tool, enter 2117514496 into the calc and the result is a hex value of 7E36B500 which is the little endian version of the same value.

The least significant digits: 01000000 - This is a big endian hex value that equates to the 't' portion in the $timestamp field so little endian hex for this is 00000001 aka '1'
 

References to other documentation:
MongoDB Documentation, https://docs.mongodb.com/manual/reference/bson-types