what are chances of bring approved for greencard when i go for interview

If you pleaded guilty to or were convicted of three marijuana offenses, you would not be approved for adjustment of status to permanent residence even if married to a US citizen with two US citizen children. The law allows for forgiveness if an offense only involves 30 g of marijuana or less for one’s own use, but that only applies to one incident, not multiple ones. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.

Admission to a controlled substance offense makes a person ineligible to adjust status. 8 U.S.C. Sec. 1255(a) provides that persons must be “admissible” in order to be eligible to adjust status to that of a lawful permanent resident. There is no waiver of inadmissibility or other grounds of relief for a person who has admitted to committing a controlled substance offense other than simple possession of 30 grams or less of marijuana. It is unclear from your post whether you were ever actually deported.  Can you clarify?