Are there any limitations for myopia (-number) for a pre-eye refraction surgery for a class 1 medical certificate? I live in India & I have -6.5 & -7.5 in the left & right eye respectively.
It looks like there are no limits for your pre-surgery eyesight:
Flight crew having undergone refractive surgery will be considered for medical fitness for flying on a case-to-case basis. Such cases will be examined only after a minimum period of six months after the procedure. Medical fitness for initial issue of licence may also be considered for such cases, if the visual requirements for the license category are met with normal corneal topography, no post surgical complications like corneal opacity interfering with vision and unstable refraction.
That makes sense: LASIK physically changes your eyes, so whatever your values were before the surgery are completely irrelevant after it. The general class I eyesight requirements in India are taken from ICAO Annex 1, which isn't freely available online. However, ICAO's Manual of Civil Aviation Medicine says:
Distant visual acuity with or without correction shall be 6/9 or better in each eye separately, and binocular visual acuity shall be 6/6 or better. No limits apply to uncorrected visual acuity.