Here is the Sanskrit anuvad, Hindi anuvad, and English translation of Atma-Samyama Yoga Chapter 6, Verse 6.37.
Sanskrit
अर्जुन उवाच । अयतिः श्रद्धयोपेतो योगाच्चलितमानसः अप्राप्य योगसंसिद्धिं कां गतिं कृष्ण गच्छति ॥ ६.३…
Hindi
अर्जुन बोले—हे श्रीकृष्ण ! जो योगमें श्रद्धा रखनेवाला है; किन्तु संयमी नहीं है, इस कारण जिसका मन अन्तकालमें योगसे विचलित हो गया है, ऐसा साधक योगकी सिद्धिको अर्थात् भगवत्साक्षात्कारको न प्राप्त होकर किस गतिको प्राप्त होता है|
English
Arjuna asked the Lord: Dear Lord Krishna, what becomes of a man who has a firm belief in Yoga and has set foot on the path of Yoga, but allows his mind to deviate or stray from this path which leads to perfection?