Dear Maduka Wehella have you read the paper from Bhojwani (1980)? Inside you can find many key tips. Consider genotypic factor: it's more important than nutritive formulation; hormones and doses, at least in my experience. Besides other reports, also check E. R. Joachim Keller and Angelika Senula Micropropagation and Cryopreservation of Garlic (Allium sativum L.). Be patience, garlic seems easy but it's not. Good luck!!!!!