Answer based on context:

In 1654 men of the Clan Chisholm raided lands belonging to Robert Munro, 3rd Baronet of Foulis. Valentine Chisholm and four other "delinquents" plundered 85 cows and 23 horses. Robert wisely pursued the matter through the courts of Oliver Cromwell. Robert Munro of Foulis accused Alexander Chisholm of Comar of allowing his kinsman to carry out the raid. The court found Robert Munro of Foulis in favour and instructed Alexander Chisholm to produce Valentine Chisholm, who was "known for his barbarity", and his four followers in court within fifteen days, compensate Foulis and his kinsmen for their losses and also to provide a £1,000 bond as security for future good behaviour. Whilst Robert Munro's lands were raided and his tenants abused, his younger brother George Munro, 1st of Newmore later commanded the king's forces in Scotland from 1674 to 1677.

Where did Robert pursue it?
the courts