"What if your Welcome" cannot be translated into Hebrew, because "your welcome" in Hebrew is literally "blessed is he/she who comes"
You can say, "what if it happens that you are permitted to enter" = ma yikreh im mutar lekha/lakh lehikanes.
welcome in Hebrew is "baroch haba" or "shalom" or "brocim habaim"
brukhim haba'im le'amritsar
Baruch Haba Le'olami - ברוך הבא לעולמי
If you are responding to "Thank you," you would say bevakasha (בבקשה) to anyone.If you are indicating that someone is welcome [in your home, etc.], you would say brucha haba'a (ברוכה הבאה) to a female.
The same way all Hebrew-speaking Jews say welcome. It depends on who you are welcoming: said to a male: baruch haba (ברוך הבא) said to a female: brucha haba'a (ברוכה הבאה) said to a group: bruchim haba'im (ברוכים הבאים) It literally means "blessed [is] he/she who comes" or "blessed [are] those who come"
Bruchim ha'baim l'knesiya ha rishona Shel yeshu b'Ivrit.
you say welcome aboard I don't know why but that seems to be the case
In Konkani, you say "svoagat" to welcome someone.
How do you say you’re welcome in Apache
brukhim haba'im, studentim ve'orchim mechubadim. ברוכים הבאים, ×¡×˜×•×“× ×ª×™× ואורחים מכובדים
brukhim haba'im latekess hasiyyum, kitah shel(ברוכים הבאים בטקס הסיום, כיתה של)
You can say "welcome" in Hindi as "स्वागत है" (pronounced as swaagat hai).