。
An elusive person.
Literal
Grasp-place [gen-の] not-existing person.
A noun fragment, not a full sentence. 捕らえどころがない ('has no place to be grasped') is a set idiom for 'elusive, hard to pin down, slippery' — used of people whose nature or intentions are hard to figure out. The どころ suffix is from 所 ('place') and attaches to a verb stem to form 'place for X-ing.' The attributive form ~のない modifies 人.