This technique is not a single universal test, it is offered as different targeted panels depending on the condition being investigated. In the Indian clinical setting, it is most commonly used for:

Hereditary breast and ovarian cancer syndrome: to look for large missing or duplicated segments in BRCA1 or BRCA2, which account for a meaningful minority of cases that sequencing alone would report as “normal”.
Lynch syndrome: to detect large rearrangements in mismatch repair genes such as MLH1, MSH2, MSH6, and PMS2, which are responsible for a notable proportion of Lynch syndrome cases.
Duchenne and Becker muscular dystrophy: to detect deletions or duplications in the DMD gene, which is the underlying cause in the majority of affected boys and men.
Spinal muscular atrophy: to count the number of copies of the SMN1 and SMN2 genes, which directly determines diagnosis and helps predict disease severity.
Familial adenomatous polyposis: to detect large deletions in the APC gene in families with strong colon polyp and cancer history.
Microdeletion and microduplication syndromes: In children with developmental delay, intellectual disability, or characteristic physical features such as Prader-Willi syndrome, Angelman syndrome, and DiGeorge syndrome
Follow-up or confirmation testing: when a sequencing report suggests a possible exon-level copy number change that needs a second, different method to confirm it

Your doctor will select the specific panel relevant to your personal or family medical history, it is never a “one size fits all” test.